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Evidence in International Investment Arbitration

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Collecting, presenting, and assessing evidence is at the very core of investor-state disputes. Investment tribunals have developed common practices regarding the taking of evidence that are reasonably well understood by the relevant participants in investor-state disputes. While such practices are welcome and have developed for good reason, tribunals should embrace arbitration’s inherent flexibility to strike an optimal balance between fact-finding accuracy, fairness, and efficiency in each case. They can and should calibrate evidentiary techniques to the specific dispute that is before them.


  • International investment law
  • Investor-State arbitration
  • Evidence
  • Admissibility of evidence
  • Burden of proof
  • Standards of evidence
  • Adverse inferences
  • Documents
  • Witnesses
  • Experts
  • Site visits and inspections
  • IBA rules on the taking of evidence

Mark W. Friedman is a partner and Guilherme Recena Costa is a senior associate at Debevoise & Plimpton LLP. The views expressed in this chapter are solely those of the authors. The authors are grateful to Juan Fandino for his contribution to this chapter.

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  1. 1.

    3 William Blackstone, Commentaries on the Laws of England 330 (1765–69), [].

  2. 2.

    Tokios Tokelés v. Ukraine, ICSID Case No. ARB/02/18, Award, 26 July 2007, ¶ 31.

  3. 3.

    See, e.g., Asian Agricultural Products Ltd v Republic of Sri Lanka, ICSID Case No. ARB/87/3, Final Award, 27 June 2000, ¶ 56 (“Rule (K) – International tribunals are not bound to adhere to strict judicial rules of evidence.”) (citations omitted) [hereinafter AAPL]; Middle East Cement Shipping and Handling Co. S.A. v. Arab Republic of Egypt, ICSID Case No. ARB/99/6, Award, 12 April 2002, ¶ 94 (“International tribunals are not bound to adhere to strict judicial rules of evidence. As a general principle the probative force of the evidence presented is for the Tribunal to determine.”); The Rompetrol Group N.V. v. Romania, ICSID Case No. ARB/06/3, Award, 6 May 2013, ¶ 181 (“[I]n international arbitration – including investment arbitration – the rules of evidence are neither rigid nor technical.”) [hereinafter Rompetrol Award]. See also Nigel Blackaby & Constantine Partasides, Redfern & Hunter on International Arbitration 377 (6 ed. 2015) [hereinafter Redfern & Hunter].

  4. 4.

    Reisman WM, Freedman EE (1982) The plaintiff’s dilemma: illegally obtained evidence and admissibility in international adjudication. Am J Int L 76: 737, 739 [hereinafter Reisman & Freedman, The Plaintiff’s Dilemma].

  5. 5.

    See Langbein JH (1996) Historical foundations of the law of evidence: a view from the Ryder sources. Colum L Rev 96: 1168, 1172 (“The essential attribute of the modern law of evidence is the effort to exclude probative but problematic oral testimony, such as hearsay, for fear of the jurors’ inability to evaluate the information properly.”) [hereinafter Langbein, Historical Foundations].

  6. 6.

    ICSID Rules of Procedure for Arbitration Proceedings Arbitration Rules, Rule 34(1) [hereinafter ICSID Arbitration Rules].

  7. 7.

    UNCITRAL Rules, Article 27(4) (“The arbitral tribunal shall determine the admissibility, relevance, materiality and weight of the evidence offered.”); IBA Rules, Article 9.1 (“The Arbitral Tribunal shall determine the admissibility, relevance, materiality and weight of evidence.”).

  8. 8.

    Brower CN (1994) Evidence before international tribunals: the need for some standard rules. Int L 28:47, 48 [hereinafter Brower, Standard Rules].

  9. 9.

    See, e.g., Saipem S.p.A. v. People’s Republic of Bangladesh, ICSID Case No. ARB/05/07, Award, 30 June 2009, ¶ 112 [hereinafter Saipem Award]; ConocoPhillips Petrozuata B.V., ConocoPhillips Hamaca B.V. and ConocoPhillips Gulf of Paria B.V. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB/07/30, Award, 8 March 2019, ¶ 264 (“The Tribunal shall be the judge of the admissibility of any evidence adduced and of its probative value. The Tribunal is thus granted full discretion in these matters. Such discretion applies also in respect of the weight to be assigned to the evidence proffered in respect of calculation of damages.”) [hereinafter ConocoPhillips Award]; Hussein Nuaman Soufraki v. United Arab Emirates, ICSID Case No. ARB/02/7, Award, 7 July 2004, ¶ 62 (“[I]t is thus for this Tribunal to consider and analyse the totality of the evidence and determine whether it leads to the conclusion that Claimant has discharged his burden of proof.”).

  10. 10.

    Rompetrol Award, supra note 3, ¶ 181.

  11. 11.

    See, e.g., Duke Energy International Peru Investments No. 1 Ltd. v. Republic of Peru, ICSID Case No. ARB/03/28, Decision on Annulment, 1 March 2011, ¶ 214 (“By ICSID Arbitration Rule 34, ‘[t]he Tribunal shall be the judge of the admissibility of any evidence adduced and of its probative value.’ It would not be proper for an annulment committee to re-evaluate that evidence, and nor is it in a position to do so.”).

  12. 12.

    Reisman & Freedman, The Plaintiff’s Dilemma, supra note 4, at 741.

  13. 13.

    Id. at 741 (noting that “evidence purposely withheld for late submission, with the intent of gaining an unfair advantage, has on occasion been rejected”). In Oostergetel v Slovak Republic, for instance, the tribunal rejected the claimant’s untimely request for tribunal-appointed experts, which was submitted only in post-hearing briefs, despite ample opportunity to adduce evidence concerning damages throughout the arbitration. See Jan Oostergetel and Theodora Laurentius v. The Slovak Republic, UNCITRAL, Final Award, 23 April 2012, ¶¶ 171–72 [hereinafter, Oostergetel Award].

  14. 14.

    Cascade Investments NV v. Republic of Turkey, ICSID Case No. ARB/18/4, Procedural Order No. 7, 26 March 2020, ¶ 28 (“In considering this issue, the Tribunal would need to consider the particular juncture actually at issue, based on when the documents became available, weighing the benefits of admitting the allegedly material information against any prejudice that might result and taking into account any mitigation steps that might be achievable.”) [hereinafter Cascade Investments PO7].

  15. 15.

    This is consistent with the overriding principle, set out in the IBA Rules, that “each Party shall act in good faith and be entitled to know, reasonably in advance of any Evidentiary Hearing or any fact or merits determination, the evidence on which the other Parties rely.” IBA Rules, Preamble, para. 3.

  16. 16.

    Berger KP (2008) The settlement privilege – a general principle of international ADR-law. Arbitr Int 24:265, 272 [hereinafter, Berger, The Settlement Privilege]; Mosk RM, Ginsburg T (2001) Evidentiary privileges in international arbitration. Int Comp L Q 50:345, 362; Sheppard A (2016) The approach of investment treaty tribunals to evidentiary privileges. ICSID Rev 31(3):670, 681–682 [hereinafter, Sheppard, Privileges].

  17. 17.

    Frontier Dispute, Judgment, I.C.J. Reports 1986, p. 554, para. 147 (quoting Factory at Chorzów, Merits, P.C.I.J., Series A, No. 17, p. 51).

  18. 18.

    IBA Rules, Article 9(3)(b).

  19. 19.

    Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Amended Confidentiality Order, 18 February 2008, ¶ 22.

  20. 20.

    Standard Chartered Bank (Hong Kong) Limited v. United Republic of Tanzania, ICSID Case No. ARB/15/41, Procedural Order No. 6b, Tribunal’s Decisions on the Claimant’s Application dated 17 November 2017 Relating to the Respondent’s Disclosure Obligations Under PO 5b, 15 January 2018, ¶ 32 [hereinafter Standard Chartered Procedural Order].

  21. 21.

    Berger, The Settlement Privilege, supra note 16, 268–9.

  22. 22.

    Standard Chartered Procedural Order, supra note 20, ¶ 32 (“[T]he ‘Without Prejudice’ privilege is borne out of the public policy of encouraging disputing parties to engage in good faith settlement to avoid contentious proceedings.”).

  23. 23.

    See Calderbank v Calderbank [1975] 3 All ER 333 (EWCA).

  24. 24.

    See generally Int’l Chamber Com., Decisions On Costs In International Arbitration 18 (2015) (“[I]n certain circumstances, the tribunal may take into account the existence of unsuccessful negotiations and/or unaccepted offers between the parties when allocating costs. There is no general provision in international arbitration for the use of settlement offers to reduce costs, but, if appropriate, it could be considered at the first case management meeting.”).

  25. 25.

    By one account, approximately 25% of investment treaties provide for some form of mandatory or voluntary consultations or negotiations between the claimant-investor and the respondent-state. See UNCTAD, Investment Policy Hub, International Investment Agreements Navigator, available at

  26. 26.

    ICSID Convention, Article 35.

  27. 27.

    Schreuer CH et al. (2009) The ICSID convention: a commentary, 2nd edn. p 453

  28. 28.

    ICSID Rules of Procedure for Conciliation Proceedings, Rule 33(3).

  29. 29.

    See Corfu Channel case, supra note 66. In Corfu Channel, the United Kingdom had conducted a mine-sweeping operation in Albanian waters to collect evidence in support of its claim for reparation of damages caused to British vessels damaged by Albanian war mines. While the ICJ did not exclude the evidence, despite having found that the United Kingdom obtained it in violation of international law, commentators consider that the judgment affirms a general norm against the admissibility of illegally obtained evidence in international proceedings. See, e.g., Reisman & Freedman, The Plaintiff’s Dilemma, supra note 4, at 747 (noting that “[t]he phenomenon of a judgment that affirms a norm, while allowing the illegal fruits of its violation to be enjoyed by the violator, is not unusual”). But see James Devaney, Evidence: International Court of Justice (ICJ), in Max Planck Encyclopedias of International Law, para. 11 (2008) (referencing the Corfu Channel Case and opining that “the ICJ has never made such a determination and in reality the more likely outcome is that the information itself would be admitted and subsequently reviewed at the fact-assessment state, and (little) weight accorded to it owing to its provenance”) [hereinafter Devaney, Evidence (ICJ)].

  30. 30.

    EDF (Services) Limited v. Romania, ICSID Case No. ARB/05/13, Procedural Order No. 3, dated 29 August 2008, ¶ 38 [hereinafter, EDF Procedural Order].

  31. 31.

    See, e.g., OOO Manolium Processing v. The Republic of Belarus, PCA Case No. 2018–06, Decision on Claimant’s Interim Measures Request, 7 December 2018, ¶ 159 (“Parties in an investment arbitration have a duty to not obtain evidence through improper means. This is derived from the obligation to arbitrate fairly and in good faith, and the principle of equality of arms implicit in all international arbitrations between a State party and a foreign investor.”); Methanex Corporation v. United States of America, UNCITRAL, Final Award of the Tribunal on Jurisdiction and Merits, 3 August 2005, Part II, Chapter I, ¶ 54 (“[T]he Disputing Parties each owed in this arbitration a general legal duty to the other and to the Tribunal to conduct themselves in good faith during these arbitration proceedings and to respect the equality of arms between them[.]”) [hereinafter Methanex Award]; Libananco Holdings Co. Limited v. Republic of Turkey, ICSID Case No. ARB/06/8, Decision on Preliminary Issues, 23 June 2008, ¶ 78 (“The Tribunal would express the principle as being that parties have an obligation to arbitrate fairly and in good faith and that an arbitral tribunal has the inherent jurisdiction to ensure that this obligation is complied with; this principle applies in all arbitration, including investment arbitration, and to all parties, including States (even in the exercise of their sovereign powers.”) [hereinafter Libananco Decision]; Glencore International A.G. and C.I. Prodeco S.A. v. Republic of Colombia, ICSID Case No. ARB/16/6, Award, 27 August 2019, ¶ 89 (“The Tribunal found that the obligation to arbitrate fairly and in good faith and the principle of equality of arms precluded Respondent from coercing evidence from Claimants through its administrative powers, and to marshal it thereafter in an investment arbitration.”) [hereinafter Glencore Award].

  32. 32.

    Methanex Award, supra note 31.

  33. 33.

    Id., Part II, Chapter I, ¶ 59.

  34. 34.

    EDF Procedural Order, supra note 30.

  35. 35.

    Id., ¶ 29.

  36. 36.

    Id., ¶ 37.

  37. 37.

    Id., ¶ 38.

  38. 38.

    Libananco Decision, supra note 31, ¶¶ 72–75.

  39. 39.

    Glencore Award, supra note 31, ¶ 25.

  40. 40.

    Libananco Decision, supra note 31, ¶ 79 (“[E]ven if Turkey can be excused for not previously having taken steps to ensure the strict separation of its criminal investigations, on the one hand, from the prosecution of this arbitration, on the other, that will not be sufficient for the future. The right and duty to investigate crime, accepted by the Tribunal above, cannot mean that the investigative power may be exercised without regard to other rights and duties, or that, by starting a criminal investigation, a State may baulk an ICSID arbitration.”); Glencore Award, supra note 31, ¶¶ 89, 647–49.

  41. 41.

    Suez, Sociedad General de Aguas de Barcelona S.A. and Vivendi Universal S.A v. Argentine Republic, ICSID Case No. ARB/03/19, Decision on Argentina’s Application for Annulment, 5 May 2017, ¶ 260 (“[I]t cannot be for the Tribunal to investigate evidence not placed before it by the Parties. In line with the generally accepted principle of ‘who asserts must prove,” which is reflected in several provisions of the ICSID Convention, it is for the parties to present their case, including evidence to prove what they assert.”). But see Metal-Tech Ltd. v. Republic of Uzbekistan, ICSID Case No. ARB/10/3, Award, 4 October 2013, ¶¶ 239–41 (considering it the tribunal’s “duty to inquire about the reasons for . . . payment” of significant sums for lobbying activities to certain “consultants” in circumstances that “raised suspicions of corruption”–“facts . . . not alleged by the Respondent [that] emerged during the Hearing in the course of the examination of the Claimant’s principal witness”) [hereinafter, Metal-Tech Award].

  42. 42.

    See, e.g., ConocoPhillips Award, supra note 9, ¶ 271 (“One is to determine the party required to submit to the Tribunal evidence relevant for the resolution of the dispute. The other is to identify the party bearing the burden of losing on a submission when the requested evidence has not been brought before this Tribunal. In many cases, but not in all cases, both components identify one and the same party.”). Accord Amaral GR (2018) Burden of proof and adverse inferences in international arbitration: proposal for an inference chart. J Int Arbitr 35(1):1, 3 [hereinafter Amaral, Adverse Inferences]; Carreteiro M (2016) Burden and standard of proof in international arbitration: proposed guidelines for promoting predictability. Rev Bras Arbitr 49: 82, 84–85.

  43. 43.

    Redfern & Hunter, supra note 3, at 378.

  44. 44.

    See, e.g., Tenaris S.A. and Talta - Trading e Marketing Sociedade Unipessoal Lda. v. Bolivarian Republic of Venezuela II, ICSID Case No. ARB/12/23, Decision on Annulment, 28 December 2018, ¶ 94 (noting that the rule on burden of proof “provides an instrument to judges and arbitrators that allows them to ascertain or reject a claim in situations of non liquet”) [hereinafter, Tenaris Annulment Decision]. See also Cheng B (1953) General principles of law as applied by international courts and tribunals. p 327 [hereinafter, Bin Cheng, General Principles].

  45. 45.

    See, e.g., Mohammad Ammar Al-Bahloul v. The Republic of Tajikistan, SCC Case No. 064/2008, Final Award, 8 June 2010 (despite the fact that the respondent-state failed to appear in the proceeding, finding that the claimant-investor failed to prove damages arising out of the respondent-state’s treaty breaches and thus denying him any recovery).

  46. 46.

    Article 53(2) of the Statute of the International Court of Justice is instructive in this respect. It provides that, before ruling against a non-appearing party, “[t]he Court must … satisfy itself, not only that it has jurisdiction … but also that the claim is well founded in fact and law.”

  47. 47.

    See, e.g., Saipem Award, supra note 9, ¶ 113 (“It is a well-established rule in international adjudication that the burden of proof lies with the party alleging a fact, whether it is the claimant or the respondent.”); Churchill Mining and Planet Mining Pty Ltd v. Republic of Indonesia, ICSID Case No. ARB/12/14 and 12/40, Award, 6 December 2016, ¶ 238 (“It is a well-established rule in international law that each Party bears the burden of proving the facts which it alleges (actori incumbit onus probandi).”) [hereinafter, Churchill Mining Award]; Georg Gavrilovic and Gavrilovic d.o.o. v. Republic of Croatia, ICSID Case No. ARB/12/39, Award, 26 July 2018, ¶ 230 (“[T]he party making an allegation bears the burden of proving it.”); Oostergetel Award, supra note 13, ¶ 146 (citing UNCITRAL Rules and noting that “[u]nder Swiss international arbitration law, this principle … is considered part of procedural ordre public”).

  48. 48.

    Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Jurisdiction and Admissibility, Judgment, I.C.J. Reports 1984, p. 392, para. 101; Article 27(1) of the UNCITRAL Rules is in accord, providing that “[e]ach party shall have the burden of proving the facts relied on to support its claim or defence.”

  49. 49.

    See, e.g., Tidewater Investment SRL and Tidewater Caribe, C.A. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB/10/5, Decision on Annulment, 27 December 2016, ¶ 160 (applying that rule to dismiss the applicant-state’s request that the award be annulled on the basis that the tribunal committed a serious departure from a fundamental procedural rule).

  50. 50.

    See, e.g., Resolute Forest Products Inc. v. Government of Canada, PCA Case No. 2016–13, Decision on Jurisdiction and Admissibility, 30 January 2018, ¶ 84 [hereinafter Resolute Forest Decision on Jurisdiction]; but see Itisaluna Iraq LLC, Munir Sukhtian International Investment LLC, VTEL Holdings Ltd., VTEL Middle East and Africa Limited v. Republic of Iraq, ICSID Case No. ARB/17/10, Award, 3 April 2020, ¶ 151 (“[T]he Tribunal observes that nothing in its analysis turns on any question of burden or standard of proof. These evidential principles address the responsibility of parties to establish the evidential case on which they rely, and typically shift between claimant and respondent to adduce a sufficiency of evidence to establish facts germane to their case. These principles do not operate in respect of contentions of international law addressed to an international tribunal which, as in this case, has a responsibility for determining the content and application of international law. Still less do they operate in respect of legal questions going to the jurisdiction of a tribunal, which a tribunal is required to address proprio motu, even if not raised by a party.”)..

  51. 51.

    See, e.g., Pac Rim Cayman LLC. v. Republic of El Salvador, ICSID Case No. ARB/09/12, Decision on Jurisdictional Objections, 1 June 2012, ¶¶ 2.11–2.15; Rompetrol Award, supra note 3, ¶ 179 (“[I]f the respondent chooses to put forward fresh allegations of its own in order to counter or undermine the claimant’s case, then by doing so the respondent takes upon itself the burden of proving what it has alleged.”).

  52. 52.

    See, e.g., David R. Aven, Samuel D. Aven, Carolyn J. Park, Eric A. Park, Jeffrey S. Shioleno, Giacomo A. Buscemi, David A. Janney and Roger Raguso v. The Republic of Costa Rica, ICSID Case No. UNCT/15/3, Final Award, 18 September 2018, ¶ 268 (“Claimants have the burden to prove the legitimate ownership of their investment.”).

  53. 53.

    Churchill Mining Award, supra note 47, ¶ 238.

  54. 54.

    See, e.g., Azurix Corp. v. The Argentine Republic (I), ICSID Case No. ARB/01/12, Decision on the Application for Annulment of the Argentine Republic, 1 September 2009, ¶ 215 (rejecting the applicant-state’s contention that “there is a general principle of law that the party that is in a better position to prove a fact bears the burden of proof,” and considering “the general principle in ICSID proceedings, and in international adjudication generally, to be that ‘who asserts must prove’, and that in order to do so, the party which asserts must itself obtain and present the necessary evidence in order to prove what it asserts.”).

  55. 55.

    See, e.g., Zhinvali Development Ltd. v. Republic of Georgia, ICSID Case No. ARB/00/1, Award, 24 January 2003, ¶ 311 (citing AAPL in support of the propositions that, “[i]n case a party adduces some evidence which prima facie supports his allegation, the burden of proof shifts to his opponent” and that “[i] n cases where proof of a fact presents extreme difficulty, a tribunal may thus be satisfied with less conclusive proof, i.e. prima facie evidence.”). But see Lao Holdings N.V. v. Lao People’s Democratic Republic (I), ICSID Case No. ARB(AF)/12/6, Decision on the Merits, 10 June 2015, ¶ 11 (noting “the Claimant’s contention that against a sovereign state a Claimant ‘is often unable to furnish direct proof of facts giving rise to responsibility’ because, as the Claimant argues, such evidence is often exclusively within the control of the Government,’” while cautioning that “a Tribunal must be careful not to shift the onus of proof from the Claimant to the Respondent Government or to bend over backwards to read in inferences against ‘the sovereign state’ that are simply not justified in the context of the whole case”); Mohammad Ammar Al-Bahloul v. The Republic of Tajikistan, SCC Case No. 064/2008, Partial Award on Jurisdiction and Liability, 2 September 2009, ¶ 115 (holding that, “[w]hile the Tribunal can understand that currently Claimant may have no or very limited access to documents in Tajikistan, this does not allow the Tribunal to make far-reaching assumptions to the detriment of Respondent.”).

  56. 56.

    Bin Cheng, General Principles, supra note 44, at 324.

  57. 57.

    Apotex Holdings Inc. and Apotex Inc. v. United States of America, ICSID Case No. ARB(AF)/12/1, Award, 25 August 2014, ¶¶ 8.6–8.10; Eli Lilly and Company v. Government of Canada, ICSID Case No. UNCT/14/2, Final Award, 16 March 2017, ¶ 109. See also Churchill Mining and Planet Mining Pty Ltd v. Republic of Indonesia, ICSID Case No. ARB/12/14 and 12/40, Decision on Annulment, 18 March 2019, ¶ 215 (“[I]t is … well accepted that placing the initial onus on a party presenting an application does not obviate the requirement, once it adduces proof of the facts on which its claims are based, that the opposing party present proof to the contrary, supporting its denial of the claim.”) [hereinafter Churchill Mining Annulment Decision].

  58. 58.

    Rompetrol Award, supra note 3, ¶ 179.

  59. 59.

    Resolute Forest Decision on Jurisdiction, ¶ 86.

  60. 60.

    Brower, Standard Rules, supra note 8, at 52 (citing Jamison M. Selby, Fact-Finding Before the Iran-United States Claims Tribunal: The View from the Trenches, in Fact-Finding Before International Tribunals: Eleventh Sokol Colloquim 135, 144 (Richard B. Lillich ed. 1992)).

  61. 61.

    See, e.g., Caratube International Oil Company LLP v. Republic of Kazakhstan (I), ICSID Case No. ARB/08/12, Decision on the Annulment Application of Caratube International Oil Company LLP, 21 February 2014, ¶ 97 (“A breach of the general principles on burden of proof can also lead to an infringement of Article 52(1)(d) of the Convention. As the committee in Klockner II stated, ‘a reversal of the burden of proof could well lead to a violation of a fundamental rule of procedure. It all depends on the importance, for the decision of the Tribunal, of the subject regarding which the burden has been reversed.’”). On the facts before it, however, the annulment committee rejected the applicant’s application for annulment of the award [Hereinafter, the Caratube Annulment Decision”].

  62. 62.

    See, e.g., Reed L (2012) Confronting complexities in fact-finding and the nature of investor-state arbitration. Am Soc Int L Proc 106:233, 234 (“A holding in an award based on failure of proof should be sufficient to withstand an annulment or setting-aside process.”).

  63. 63.

    Tenaris Annulment Decision, supra note 44, ¶¶ 93, 96 (citing Caratube Annulment Decision, supra note 61).

  64. 64.

    Ampal-American Israel Corporation and others v. Arab Republic of Egypt, ICSID Case No. ARB/12/11, Decision on Jurisdiction, 1 February 2016, ¶ 219 (citing Bin Cheng, General Principles, supra note 44, at 329) (“[A] party having the burden of proof must not only bring evidence in support of his allegations, but must also convince the Tribunal of their truth, lest they be disregarded for want, or insufficiency, of proof.”).

  65. 65.

    Rompetrol Award, supra note 3, ¶ 178 (“[T]he burden of proof defines which party has to prove what, in order for its case to prevail; the standard of proof defines how much evidence is needed to establish either an individual issue or the party’s case as a whole.”).

  66. 66.

    See Corfu Channel case, Judgment of April 9th, 1949, I.C.J. Reports 1949, p. 4, at 18 (“[T]he other State, the victim of a breach of international law, is often unable to furnish direct proof of facts giving rise to responsibility. Such a State should be allowed a more liberal recourse to inferences of fact and circumstantial evidence. This indirect evidence is admitted in all systems of law, and its use is recognized by international decisions. It must be regarded as of special weight when it is based on a series of facts linked together and leading logically to a single conclusion.”). See also Rumeli Telekom A.S. and Telsim Mobil Telekomunikasyon Hizmetleri A.S. v. Republic of Kazakhstan, ICSID Case No. ARB/05/16, Award, 29 July 2008, ¶ 444 (citing Corfu Channel and noting that “[i]n general, international tribunals have given full weight to circumstantial evidence”). But see Bayindir Insaat Turizm Ticaret Ve Sanayi A.S. v. Islamic Republic of Pakistan, ICSID Case No. ARB/03/29, Award, 27 August 2009, ¶ 142 (taking note of Corfu Channel but holding that a tribunal has “to assess whether or not the [circumstantial] evidence produced … is sufficient to exclude any reasonable doubt” and denying to draw the inference sought on the facts before it) [hereinafter Bayindir Award].

  67. 67.

    See, e.g., Bernhard von Pezold and others v. Republic of Zimbabwe, ICSID Case No. ARB/10/15, Award, 28 July 2015, ¶ 177 (“In general, the standard of proof applied in international arbitration is that a claim must be proven on the ‘balance of probabilities.’”); see also Brower, Standard Rules, supra note 8, at 49 (“[T]he level of proof is not capable of precise definition and may be safely assumed to be close to what has been called the ‘balance of probabilities[.]’”).

  68. 68.

    See, e.g., PNG Sustainable Development Program Ltd. v. Independent State of Papua New Guinea, ICSID Case No. ARB/13/33, Award, 5 May 2015, ¶ 255 (“[T]he issue [of a State’s submission to ICSID jurisdiction] is … to be approached objectively and neutrally, aiming to ascertain the true intentions of the relevant party (or parties) in a particular instrument. Where relevant, the standard of proof is generally held to be a preponderance of the evidence or a balance of probabilities.”).

  69. 69.

    See, e.g., Ioan Micula, Viorel Micula and others v. Romania (II), ICSID Case No. ARB/14/29, Award, 5 March 2020, ¶ 378 (“[A]llegations of bad faith require a high standard of proof.”); Oded Besserglik v. Republic of Mozambique, ICSID Case No. ARB(AF)/14/2, Award, 28 October 2019, ¶ 362 (“The standard of proof for a conspiracy involving a component of bad faith is a demanding one. The same is true for collusion.”); South American Silver Limited (Bermuda) v. The Plurinational State of Bolivia, PCA Case No. 2013–15, Award, 22 November 2018, ¶ 673 (“Such an allegation requires a high standard of proof as it entails establishing an act of the State in bad faith or intolerable negligence.”); UAB E energija (Lithuania) v. Republic of Latvia, ICSID Case No. ARB/12/33, Award of the Tribunal, 22 December 2017, ¶ 541 (“[T]he standard of proof should be appropriately high considering, first, that as a general matter bona fide conduct must be presumed in principle.”).

  70. 70.

    See, e.g., Karkey Karadeniz Elektrik Uretim A.S. v. Islamic Republic of Pakistan, ICSID Case No. ARB/13/1, Award, 22 August 2017, ¶ 492(“[T]he seriousness of the accusation of corruption in the present case, including the fact that it involves officials at the highest level of the Pakistani Government at the time, requires clear and convincing evidence.”); EDF (Services) Limited v. Romania, (ICSID Case No. ARB/05/13), Award, 8 October 2009, ¶ 221 (“The seriousness of the accusation of corruption in the present case, considering that it involves officials at the highest level of the Romanian Government at the time, demands clear and convincing evidence. There is general consensus among international tribunals and commentators regarding the need for a high standard of proof of corruption.”); Fraport AG Frankfurt Airport Services Worldwide v. Republic of the Philippines (II), ICSID Case No. ARB/11/12, Award, 10 December 2014, ¶ 479 (“[C]onsidering the difficulty to prove corruption by direct evidence, the same may be circumstantial. However, in view of the consequences of corruption on the investor’s ability to claim the BIT protection, evidence must be clear and convincing so as to reasonably make-believe that the facts, as alleged, have occurred.”); Bayindir Award, supra note 67, ¶ 143 (“The Tribunal further considers that, as argued by the Respondent, the standard for proving bad faith is a demanding one, in particular if bad faith is to be established on the basis of circumstantial evidence.”).

  71. 71.

    See, e.g., Rompetrol, supra note 3, ¶ 182 (“[T]he Tribunal, while applying the normal rule of the ‘balance of probabilities’ as the standard appropriate to the generality of the factual issues before it, will where necessary adopt a more nuanced approach and will decide in each discrete instance whether an allegation of seriously wrongful conduct by a Romanian state official at either the administrative or policymaking level has been proved on the basis of the entire body of direct and indirect evidence before it.”); Churchill Mining Award, supra note 47, ¶ 24 (“[T]he Respondent carries the burden of proving forgery and fraud, which proof will be measured on a standard of balance of probabilities or intime conviction taking into account that more persuasive evidence is required for implausible facts … . The Tribunal will assess all the available evidence on record and weigh it in the context of all relevant circumstances.”).

  72. 72.

    Secretary of State for the Home Department v. Rehman [2001] UKHL 47, at [55].

  73. 73.


  74. 74.

    But see World Duty Free Company v. Republic of Kenya, ICSID Case No. ARB/00/7, Award, 4 October 2006 (dismissing the claimant’s claims on the basis of illegality); Metal-Tech Award, supra note 41 (same).

  75. 75.

    Khan Resources Inc., Khan Resources B.V. and Cauc Holding Company Ltd. v. the Government of Mongolia and Monatom Co., Ltd., PCA Case No. 2011–09, Award, 2 March 2015, ¶ 375 (“The standard of proof required is the balance of probabilities. This, of course, means that damages cannot be speculative or uncertain. However, scientific certainty is not required and it is widely acknowledged by investment treaty tribunals and publicists that the assessment of damages is often a difficult exercise and will usually involve some degree of estimation[.]”).

  76. 76.

    See, e.g., Crystallex International Corporation v. Bolivarian Republic of Venezuela, ICSID Case No. ARB(AF)/11/2, Award, 4 April 2016, ¶ 875(“[O]nce the fact of future profitability is established and is not essentially of speculative nature, the amount of such profits need not be proven with the same degree of certainty. In other words, the Claimant must prove that it has been deprived of profits that would have actually been earned. This requires proving that there is sufficient certainty that it had engaged or would have engaged in a profitmaking activity but for the Respondent’s wrongful act, and that such activity would have indeed been profitable.”); Joseph Charles Lemire v. Ukraine, ICSID Case No. ARB/06/18, Award, 28 March 2011, ¶ 246 (“[I]t is a commonly accepted standard for awarding forward looking compensation that damages must not be speculative or uncertain, but proved with reasonable certainty; the level of certainty is unlikely, however, to be the same with respect to the conclusion that damages have been caused, and the precise quantification of such damages. Once causation has been established, and it has been proven that the in bonis party has indeed suffered a loss, less certainty is required in proof of the actual amount of damages; for this latter determination Claimant only needs to provide a basis upon which the Tribunal can, with reasonable confidence, estimate the extent of the loss.”); Tethyan Copper Company Pty Limited v. Islamic Republic of Pakistan, ICSID Case No. ARB/12/1, Award, 12 July 2019, ¶ 297 (“[T]he standard of proof cannot be such as to exclude a valuation because the Tribunal is not ‘certain’ that the result it produces is correct in terms of ‘scientifically precise.’ On the other hand, the Tribunal must be convinced that the valuation is appropriate in that it will produce a sufficiently reliable result.”).

  77. 77.

    Marco Gavazzi and Stefano Gavazzi v. Romania, ICSID Case No. ARB/12/25, Excerpts of Award, 18 April 2017, ¶ 224.

  78. 78.

    See, e.g., IBA Rules, Article 9.5.

  79. 79.

    Luttrell S (2018) Ten things to consider when seeking adverse inferences in international arbitration. Under 40 Int Arbitr 40:281, 286–87 [hereinafter Luttrell, Ten Things].

  80. 80.

    Greenberg S, Lautenschlager F (2011) Adverse inferences in international arbitral practice. ICC Int Court of Arbitr Bull 22(2):43, 46 [hereinafter Greenberg & Lautenschlager, Adverse Inferences].

  81. 81.

    See Luttrell, Ten Things, supra note 79, at 286 (noting that “an adverse inference can only be requested by the party that bears the burden of proof on the issue to which the missing evidence relates”).

  82. 82.

    See, e.g., IBA Rules, Article 9.7.

  83. 83.

    IBA Rules, Articles 9.5, 9.6.

  84. 84.

    Luttrell, Ten Things, supra note 79, at 288 (noting that “it is not unusual to see adverse inferences requested in circumstances where the inference proponent has not earlier sought the evidence in question”). As that author notes, the problem is particularly frequent with respect to witness testimony, even though most arbitration laws and rules empower tribunals to direct the parties to produce witnesses for examination. Id. at 289.

  85. 85.

    See generally Jeremy Sharpe, Drawing Adverse Inferences from the Non-Production of Evidence, 22(4) Arb. Int’l 549 (2006) [hereinafter, Sharpe, Adverse Inferences]. Accord Amaral, Adverse Inferences, supra note 42 (endorsing the so-called “Sharpe Test”); Luttrell, Ten Things, supra note 79, at 282–83 (same).

  86. 86.

    See, e.g., Conocophillips Petrozuata B.V., Conocophillips Hamaca B.V. and Conocophillips Gulf of Paria B.V. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB/07/30, Interim Decision, 17 January 2017, ¶70 (reasoning that where “both Parties failed to provide any evidence … no adverse inference can be attributed to any of them for such reason”).

  87. 87.

    See Bin Cheng, General Principles, supra note 44, at 325 (“The inference in every case must, however, be one which can reasonably be drawn.”).

  88. 88.

    See, e.g., Thai Lao Lignite (Thailand) Co. v. Gov’t of Lao People’s Democratic Republic, No. 10 CIV. 5256 KMW DCF, 2013 WL 3970823, at *6 (S.D.N.Y. Aug. 2, 2013) (noting that “the party seeking an adverse inference must adduce sufficient evidence from which a reasonable trier of fact could infer that the … unavailable evidence would have been of the nature alleged,” and, upon finding that the petitioners had failed to do so, rejecting a request for adverse inferences with respect to the relationship between the respondent and a government instrumentality in the context of award enforcement) (internal quotation marks omitted); Luttrell, Ten Things, supra note 79, at 284 (citing Wiszniewski v Central Manchester Authority [1998] 1 Lloyd’s Rep (Med) 223).

  89. 89.

    See Polkinghorne M, Rosenberg C (2015) The adverse inference in ICSID practice. ICSID Rev–For Inv L J 30(3):741, 751; see also Devaney, Evidence (ICJ), supra note 29, para. 34 (“[I]n practice the ICJ has never explicitly drawn adverse inferences from any refusal to comply with requests for information made under Article 49 [of the ICJ Statute].”). But see Metal-Tech Award, supra note 41, ¶ 265 (drawing inference that no legitimate services were rendered where claimant failed to produce documents or testimony evidencing the purpose of services performed by so-called consultants); Europe Cement Investment & Trade S.A. v. Republic of Turkey, Award, 13 August 2009, ¶¶ 163–64 (drawing inference that claim based on bearer share certificates was fraudulent where claimant failed to produce originals of the share agreements or the share certificates themselves, despite being requested to do so).

  90. 90.

    See Greenberg & Lautenschlager, Adverse Inferences, supra note 80, at 44 (noting that, “in an attempt to be pragmatic, they quite often skirt around the adverse inference contention, preferring to tread safely and rely on other evidence”).

  91. 91.

    OPIC Karimum Corporation v. The Bolivarian Republic of Venezuela, ICSID Case No. ARB/10/14, Award, 28 May 2013.

  92. 92.

    Id. ¶ 105.

  93. 93.

    Id. ¶ 125.

  94. 94.

    Id. ¶ 145.

  95. 95.

    Id. ¶ 146.

  96. 96.

    See, e.g., United Mexican States v Marvin Roy Feldman Karpa, 74 OR 3d 180 (2005) (refusing application to set aside Marvin Roy Feldman Karpa v. United Mexican States, ICSID Case No. ARB(AF)/99/1, Award, 16 December 2002).

  97. 97.

    Churchill Mining Annulment Decision, supra note 57, ¶ 220.

  98. 98.


  99. 99.

    Redfern & Hunter, supra note 3, at 380; see also Brower, Standard Rules, supra note 8, at 54–55 (describing the practice of the Iran-United States Claims Tribunal); Devaney, Evidence (ICJ), supra note 29, paras. 6, 17 (2008) (describing ICJ practice).

  100. 100.

    ICSID Arbitration Rules, Article 33; UNCITRAL Rules, Articles 20.4, 21.2; IBA Rules, Article 3.1 (“Within the time ordered by the Arbitral Tribunal, each Party shall submit to the Arbitral Tribunal and to the other Parties all Documents available to it on which it relies, including public Documents and those in the public domain, except for any Documents that have already been submitted by another Party.”).

  101. 101.

    See, e.g., UNCITRAL Rules, Articles 20.4, 21.2.

  102. 102.

    See, e.g., UNCITRAL Rules, Article 19.2; IBA Rules, Article 3.12(d).

  103. 103.

    IBA Rules, Article 3.12(a).

  104. 104.

    ICSID Convention, Article 43(a). Accord ICSID Arbitration Rules, Rule 34(2)(a); UNCITRAL Arbitration Rules, Article 27(3) (“At any time during the arbitral proceedings the arbitral tribunal may require the parties to produce documents, exhibits or other evidence within such a period of time as the arbitral tribunal shall determine”); IBA Rules, Article 3.10.

  105. 105.

    See, e.g., Tokios Tokelés v. Ukraine, ARB/02/18, Procedural Order No. 3, 18 January 2005, ¶ 25 (“Under Article 43 of the Convention and Arbitration Rule 34(2)(a), the Tribunal may “call upon the parties to produce documents” if the Tribunal “deems it necessary” to do so.”); see also Quadrant Pacific Growth Fund L.P. and Canasco Holdings Inc. v. Republic of Costa Rica, ICSID Case No. ARB(AF)/08/1, Order of the Tribunal Taking Note of the Discontinuance of the Proceedings and Allocation of Costs, 27 October 2010, ¶ 35 (reserving the tribunal’s “power to request, up to the time of rendering the award, the production of any additional document the Tribunal finds relevant to the outcome of this arbitration”); Niko Resources (Bangladesh) Ltd. v. Bangladesh Petroleum Exploration and Production Company Limited and Bangladesh Oil Gas and Mineral Corporation, ICSID Case Nos. ARB/10/11 and ARB/10/18, Procedural Order No. 18, 23 March 2017, ¶ 68 (“Article 43 of the ICSID Convention, which deals with evidence, specifically empowers an ICSID tribunal, under paragraph (a) to call upon the parties to produce documents or other evidence. In this regard the Convention lays the primary responsibility on the parties to assist the Tribunal by bringing forward the evidence necessary to the fair disposition of the dispute.”) [hereinafter Niko Resources PO18].

  106. 106.

    See, e.g., IBA Rules, Article 2.1.

  107. 107.

    See, e.g., Rules on the Efficient Conduct of Proceedings in International Arbitration, Note from the Working Group, at 2 (2018) (the “Prague Rules”) (purporting to “increase efficiency of arbitral proceedings [by] encourag[ing] tribunals to take a more active role in managing the proceedings (as is traditionally done in many civil law countries)”).

  108. 108.

    Commentary on the Revised Text of the 2010 IBA Rules on the Taking of Evidence in International Arbitration, 5 Disp. Resol. Int’l 45, 53–54 (2011) [hereinafter Commentary on the IBA Rules].

  109. 109.

    Fed. R. Evid. 401.

  110. 110.

    Redfern & Hunter, supra note 3, at 382.

  111. 111.

    Commentary on the IBA Rules, supra note 108, at 56.

  112. 112.

    See Yves Derains, Towards Greater Efficiency in Document Production before Arbitral Tribunals-A Continental Viewpoint, ICC Int’l Court of Arb. Bull. (Special Supplement - Document Production in International Arbitration) 83, 87 (2006) (“When assessing requests arbitrators must carefully check that the burden of proof actually lies on the requesting party”); but see Gary Born, International Commercial Arbitration 2364 (2d ed. 2014) (“[I]it is both illogical and unfair to deny a party disclosure of documents otherwise subject to disclosure, merely because it does not bear the burden of proof with respect to the underlying issues to which the document is relevant.”) [hereinafter Born, ICA].

  113. 113.

    Libananco Holdings Co. Limited v. Republic of Turkey, ICSID Case No. ARB/06/8, Decision on Preliminary Issues, 23 June 2008, ¶ 78.

  114. 114.

    See, e.g., IBA Rules, Articles 9.3(c) and 9.3(e). See also Commentary on the IBA Rules, supra note 108, at 75 (“Article 9.3(c) expresses the guiding principle that expectations of the parties and their advisors at the time the legal impediment or privilege is said to have arisen should be taken into consideration.”).

  115. 115.

    See Sheppard, Privileges, supra note 16, at 676–77.

  116. 116.

    IBA Rules, Article 9.3(e).

  117. 117.

    See, e.g., Tawil G, Lima I (2009) Privilege-related issues in international arbitration. In: Mourre A, Giovannini T (eds) Written evidence and discovery in international arbitration: new issues and tendencies. p 29, 43 (reasoning that, “absent uniform substantial rules on the matter, [the most-favoured-rule] method appears to be the most suitable one”); Sheppard, Privileges, supra note 16, at 677; Commentary on the IBA Rules, supra note 108, 76–77 (citing the “catch-all” provision in Article 9.2(g) as allowing this solution).

  118. 118.

    See, e.g., Glamis Gold Ltd. v. United States of America, Decision on Parties’ Requests for Production of Documents Withheld on Grounds of Privilege, 17 November 2005, ¶ 23.

  119. 119.

    Commentary on the IBA Rules, supra note 108, at 76.

  120. 120.


  121. 121.


  122. 122.

    William Ralph Clayton, William Douglas Clayton, Daniel Clayton and Bilcon of Delaware, Inc. v. Government of Canada, PCA Case No. 2009–04, Procedural Order No. 13, 11 July 2012, ¶ 22 [hereinafter, Clayton and Bilcon, Procedural Order].

  123. 123.

    Sheppard, Privileges, supra note 16, at 689. See also id. at 682–87 (discussing specific investor-state cases).

  124. 124.

    Clayton and Bilcon, Procedural Order, supra note 122, ¶ 24.

  125. 125.

    See Commentary on the IBA Rules, supra note 108, at 57–58.

  126. 126.

    IBA Rules, Article 3.8.

  127. 127.

    Churchill Mining Annulment Decision, supra note 57, ¶ 211 (“The obligation of the parties to cooperate with each other and with the tribunal in the production of evidence is a general principle of international arbitration.”).

  128. 128.

    Redfern & Hunter, supra note 3, at 384.

  129. 129.


  130. 130.

    See, e.g., Gramercy Funds Management LLC, and Gramercy Peru Holdings LLC v. The Republic of Peru, ICSID Case No. UNCT/18/2, Procedural Order No. 3, 12 July 2018.

  131. 131.

    IBA Rules, Article 3.9.

  132. 132.

    IBA Rules, Article 3.13.

  133. 133.

    28 U.S.C. § 1782.

  134. 134.

    28 U.S.C. § 1782(a).

  135. 135.

    See, e.g., In re Application of Chevron Corp., 709 F. Supp. 2d 283, 291 (S.D.N.Y. 2010), as corrected (May 10, 2010), aff’d sub nom. Chevron Corp. v. Berlinger, 629 F.3d 297 (2d Cir. 2011) (holding that “international arbitral bodies operating under UNCITRAL rules constitute ‘foreign tribunals’ for purposes of Section 1782”); Republic of Ecuador v. Bjorkman, 801 F. Supp. 2d 1121, 1124 (D. Colo. 2011), aff’d, No. 11-CV-01470-WYD-MEH, 2011 WL 5439681 (D. Colo. Nov. 9, 2011) (noting “significant agreement at the district court level that, after the Supreme Court’s dicta in Intel Corp., international arbitral bodies operating under UNCITRAL rules constitute ‘foreign tribunals’ for purposes of Section 1782”) (citations omitted).

  136. 136.

    Cascade Investments PO7, supra note 14, ¶¶ 29–30.

  137. 137.

    Niko Resources PO18, supra note 105, ¶ 70.

  138. 138.


  139. 139.

    See, e.g., IBA Rules, Article 4.2. Cf. Brower, Standard Rules, supra note 8, at 49 (reporting on the practice of the Iran-United States Claims Tribunal, according to which “[w]itnesses give ‘testimony’ while interested parties only provide ‘information’”).

  140. 140.

    See Born, ICA, supra note 112, at 2260.

  141. 141.

    See IBA Rules, Article 8.1.

  142. 142.

    See id.

  143. 143.

    See id., Article 4.7.

  144. 144.

    See id., Article 4.8.

  145. 145.

    [1894] 6 R 67.

  146. 146.

    See, e.g., P v D [2019] EWHC 1277 (Comm) (setting aside an arbitral award on the basis that the tribunal made findings of fact on an issue that had not properly been put to a witness on cross-examination).

  147. 147.

    Commentary on the IBA Rules, supra note 108, at 63.

  148. 148.

    IBA Rules, Article 4.3.

  149. 149.

    The same rule applies in proceedings before the ICJ. See International Court of Justice, Rules of Court (1978), Article 65 (“Before testifying, witnesses shall remain out of court.”).

  150. 150.

    The IBA Rules provide that “[q]uestions to a witness during direct and re-direct testimony may not be unreasonably leading.” IBA Rules, Article 8.2.

  151. 151.

    Cf. Brower, Standard Rules, at 51–52 (noting that such practice was not common in the Iran-United States Claims Tribunal, to the point of it being “generally ill-advised” to conduct cross-examination).

  152. 152.

    See generally Hobér KI, Sussman HS (2014) Cross-examination in international arbitration.

  153. 153.

    See IBA Rules, Article 8.2 (“The Arbitral Tribunal may limit or exclude any question to, answer by or appearance of a witness, if it considers such question, answer or appearance to be irrelevant, immaterial, unreasonably burdensome, duplicative or otherwise covered by a reason for objection set forth in Article 9.2.”).

  154. 154.

    See generally Mirjan Damaška, Presentation of Evidence and Factfinding Precision, 123 U. Penn. L.R. 1083 (1975) (addressing the adversarial and inquisitorial approaches to the development of witness testimony).

  155. 155.

    See IBA Rules, Article 8.3.(a).

  156. 156.

    See id., Article 8.2.

  157. 157.

    See id., Article 8.3.(a).

  158. 158.

    CIArb Protocol, Preamble ¶ 4(ii).

  159. 159.

    CIArb Protocol, Article 8(c).

  160. 160.

    Cf. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) (endorsing a five-factor test that applies to determine whether an expert’s testimony should be admitted as an application of valid scientific methodology).

  161. 161.

    CIArb Protocol, Article 4.1.

  162. 162.

    Bridgestone Americas, Inc. and Bridgestone Licensing Services, Inc. v. Republic of Panama, ICSID Case No. ARB/16/34, Tribunal’s Ruling on Claimants’ Application to Remove the Respondent’s Expert as to Panamanian Law, 13 December 2018, ¶ 16 [hereinafter, Bridgestone Ruling].

  163. 163.

    Commentary on the IBA Rules, supra note 108, at 68.

  164. 164.

    Flughafen Zürich A.G. and Gestión e Ingenería IDC S.A. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB/10/19, Decision on proposal for disqualification of expert witness and exclusion of evidence, 29 August 2012; Bridgestone Ruling, supra note 162.

  165. 165.

    Bridgestone Ruling, supra note 162, ¶ 23.

  166. 166.

    Bridgestone Ruling, supra note 162, ¶ 27.

  167. 167.

    See, e.g., Meat Corporation of Namibia Ltd v Dawn Meats (UK) Ltd. [2011] EWHC 474 (Ch). Accepting instructions from one of the parties to a dispute may, however, give rise to a duty of loyalty on the part of the expert (which can extend to a group of companies with which that expert is affiliated) and disqualify him or her from being engaged by an adverse party in a related proceeding. See, e.g., A Company v X, Y and Z [2020] EWHC 809 (TCC) (extending an interim injunction enjoining a global consultancy firm from acting as independent experts in related arbitration proceedings against the claimant).

  168. 168.

    Blackaby N, Wilbraham A (2016) Practical issues relating to the use of expert evidence in investment treaty arbitration. ICSID Rev 31(3):655, 660–661 [hereinafter Blackaby & Wilbraham, Practical Issues].

  169. 169.

    Donovan DF (2018) Re-examining the legal expert in international arbitration (Eleventh Kaplan lecture, 15 November 2017). In: International arbitration: issues, perspective and practice: Liber Amicorum Neil Kaplan. pp 247, 248 [hereinafter Donovan, Re-Examining the Legal Expert].

  170. 170.

    Fidel v. Felecia & Faraz [2015] DIFC CA 002, Claim No. CA 002/2015 (23 November 2015), para. 72 [hereinafter, Fidel].

  171. 171.

    See Donovan, Re-Examining the Legal Expert, supra note 169, at 255–58. See also Bodum USA, Inc. v. La Cafetière, Inc., 621 F.3d 624 (7th Cir. 2010) (Judges Easterbrook and Posner opining against the use of legal experts and in favor of direct argument by counsel on issues of foreign law); Fidel, supra note 170 (same).

  172. 172.

    Blackaby & Wilbraham, Practical Issues, supra note 168, at 668.

  173. 173.

    See IBA Rules, Article 6.1.

  174. 174.

    See, e.g., Perenco Ecuador Limited v. Republic of Ecuador, ICSID Case No. ARB/08/6, Interim Decision on the Environmental Counterclaim, 11 August 2015, ¶¶ 585–87. Cf. RREEF Infrastructure (G.P.) Limited and RREEF Pan-European Infrastructure Two Lux S.à r.l. v. Kingdom of Spain, ICSID Case No. ARB/13/30, Decision on Responsibility and on the Principles of Quantum, 30 November 2018, ¶¶ 592–95 (considering it more appropriate, in similar circumstances, to establish certain principles of quantum and direct the parties and their respective quantum experts to attempt to reach agreement on the relevant disputed issues, while reserving the right to appoint its own expert if that attempt fails to resolve those issues).

  175. 175.

    See Blackaby & Wilbraham, Practical Issues, supra note 168, at 664.

  176. 176.

    See Born, ICA, supra note 112, at 2280.

  177. 177.

    Jones D (2008) Party appointed expert witnesses in international arbitration: a protocol at last. Arbitr Int 24(1):137, 154

  178. 178.

    See IBA Rules, Article 5.2(b).

  179. 179.

    See id., Article 5.2(c), (g).

  180. 180.

    See id., Article 5.2(d).

  181. 181.

    See id., Article 5.2(e).

  182. 182.

    See CIArb Protocol, Article 4.4.

  183. 183.

    See id., Article 8.

  184. 184.

    See id., Article 5.1.

  185. 185.

    See id., Article 5.2.

  186. 186.

    See id., Article 6.1(a).

  187. 187.

    See id., Article 6.1(b).

  188. 188.

    See id., Article 6.1(h).

  189. 189.

    See Born, ICA, supra note 112, at 2289.

  190. 190.

    Id. at 2293.

  191. 191.


  192. 192.

    ICSID Convention, Article 43(b) (“[T]he Tribunal may, if it deems it necessary at any stage of the proceedings, . . . visit the scene connected with the dispute, and conduct such inquiries there as it may deem appropriate.”); ICSID Arbitration Rules, Rule 34(2)(b) (reproducing ICSID Convention Article 43) and Rule 37(1) (“If the Tribunal considers it necessary to visit any place connected with the dispute or to conduct an inquiry there, it shall make an order to this effect. The order shall define the scope of the visit or the subject of the inquiry, the time limit, the procedure to be followed and other particulars. The parties may participate in any visit or inquiry.”).

  193. 193.

    IBA Rules, Article 7.

  194. 194.

    See Born, ICA, supra note 112, at 2353.

  195. 195.

    See, e.g., Jeffery Commission & Rahim Moloo, Procedural Issues in International Investment Arbitration 161 (2018) (noting that, as of 2017, site visits figured in only 2% of publicly available cases) [hereinafter Commission & Moloo, Procedural Issues]; Redfern & Hunter, supra note 3, at 399. See also Ioan Micula and others v. Romania I, ICSID Case No. ARB/05/20, Award, 11 December 2013, ¶ 114 (concluding that site visit proposed by claimants and objected to by respondent was neither necessary nor useful). Tribunals are sometimes reluctant to conduct site visits even where the parties have so requested. See, e.g., Compañia del Desarrollo de Santa Elena S.A. v. Republic of Costa Rica, ICSID Case No. ARB/96/1, Award, 17 February 2000, ¶ 14.

  196. 196.

    Marion Unglaube v. Republic of Costa Rica, ICSID Case No. ARB/08/1, Award, 16 May 2012, ¶ 165.

  197. 197.

    See Mr. Cornelis Willem van Noordenne, Mr. Bartus van Noordenne, Stichting Administratiekantoor Anbadi, Estudios Tributarios AP S.A. and Álvarez y Marín Corporación S.A. v. Republic of Panama, ICSID Case No. ARB/15/14, Award, 12 October 2018, ¶ 40 [hereinafter Álvarez y Marín Award].

  198. 198.

    See Elsamex, S.A. v. Republic of Honduras, ICSID Case No. ARB/09/4, Award, 16 November 2012, ¶¶ 382, 477–79. See also Kinnear M, Ayman R (2015) Site visits in ICSID arbitration. In: Carlevaris A et al. (eds) International arbitration under review: essays in honour of John Beechey. p 247, 253 (noting that the Elsamex tribunal highlighted “the utility of that visit at several points in its award, asserting that the visit contributed to the fact findings concerning the condition of the disputed highway”) [hereinafter Kinnear & Ayman, Site Visits].

  199. 199.

    See Burlington Resources, Inc. v. Republic of Ecuador, ICSID Case No. ARB/08/5, Decision on Counterclaims, 7 February 2017, ¶ 18 [hereinafter Burlington Decision on Counterclaims].

  200. 200.

    See ICSID Arbitration Rules, Rule 37(1); IBA Rules, Rule 7. See also Redfern & Hunter, supra note 3, at 399; Kinnear & Ayman, Site Visits, supra note 198, at 254–55; Commission & Moloo, Procedural Issues, supra note 195, 163–64.

  201. 201.

    See, e.g., Kinnear & Ayman, Site Visits, supra note 198, at 255–58; Commission & Moloo, Procedural Issues, supra note 195, at 164–65. For a particularly comprehensive description of these details, see, e.g., Burlington Decision on Counterclaims, supra note 199, ¶¶ 18–33.

  202. 202.

    Kinnear & Ayman, Site Visits, supra note 198, at 254.

  203. 203.

    Burlington Decision on Counterclaims, supra note 199, ¶ 21.

  204. 204.

    IBA Rules, Article 6.3.

  205. 205.

    See Adel A Hamadi Al Tamimi v. Sultanate of Oman, ICSID Case No. ARB/11/33, Procedural Order No. 2, 28 September 2012, ¶ 6, 15.

  206. 206.

    See Enkev Beheer BV v. Republic of Poland, UNCITRAL, PCA Case No. 2013–01, First Partial Award, 29 April 2014, ¶ 39.

  207. 207.

    See BSG Resources Limited and ors v Guinea, ICSID Case No. ARB/14/22, Procedural Order No. 14 (Document Inspection), 28 August 2017, ¶ 3, Annex 1.

  208. 208.

    See, e.g., Álvarez y Marín Award, supra note 197, ¶ 424 (while deciding whether to uphold Panama’s earlier undertaking to assume the costs of the ocular inspection, the tribunal held: “the Inspection was not significantly relevant to the decision of the case and, as such, it was not determinative. It must thus be the Respondent who assumes the costs of the Ocular Inspection.”) [original in Spanish].

  209. 209.

    David W. Rivkin, Towards a New Paradigm in International Arbitration: The Town Elder Model Revisited, 24(3) Arb. Int’l 375, 378 (2008).

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Friedman, M.W., Recena Costa, G. (2021). Evidence in International Investment Arbitration. In: Chaisse, J., Choukroune, L., Jusoh, S. (eds) Handbook of International Investment Law and Policy. Springer, Singapore.

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