The term “evidence” (noun) dates back to c. 1300, "appearance from which inferences may be drawn", from Old French evidence, from Late Latin evidentia "proof", in classical Latin "distinction, vivid presentation, clearness". As a verb, it means to show clearly, prove, give evidence of, c. 1600, from “evidence” (n.).1
II. Powers of the arbitral tribunal
A. Under the ICSID Convention and Arbitration Rules
Pursuant to the ICSID Convention (Article 44), “[a]ny arbitration proceeding shall be conducted in accordance with the provisions of [Section 3 (Powers and Functions of the Tribunal, Articles 41-47) of Chapter IV (Arbitration)] and, except as the Parties otherwise agree, in accordance with the Arbitration Rules. […] If any question of procedure arises which is not covered by this Section or the Arbitration Rules or any rules agreed by the Parties, the Tribunal shall decide the question.”2
Article 43 provides that, “[e]xcept as the Parties otherwise agree, the Tribunal may, if it deems it necessary at any stage of the proceedings, (a) call upon the Parties to produce documents or other evidence, and (b) visit the scene connected with the dispute, and conduct such inquiries there as it may deem appropriate.”3
The Rompetrol award notes that the intention behind Articles 43-45 of the ICSID Convention is “plainly that a tribunal should possess a large measure of discretion over how the relevant facts are to be found and to be proved”. And that this “general principle […] finds strong reinforcement in the Arbitration Rules, notably in paragraphs (1) and (3) of Rule 34.”4
Moreover, the Gavrilovic tribunal considers that, “[i]n the absence of mandatory rules as to how a tribunal should judge the probative value of evidence, […] it [is] appropriate to apply the general approach taken in international dispute settlement which is not characterised by formal rules of evidence.”6
ICSID Arbitration Rules, Rule 34(1); 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, para. 264; Saipem S.p.A. v. People's Republic of Bangladesh, ICSID Case No. ARB/05/07, Award, 30 June 2009, para. 112; Asian Agricultural Products LTD (AAPL) v. Republic of Sri Lanka, ICSID Case No. ARB/87/3, Final Award, 27 June 1990, para. 56.
B. Under other rules
With regard to the International Chamber of Commerce Rules, Article 25 is dedicated to establishing the facts of the case.
III. IBA Rules of Evidence
A. Relevance, scope and principles
The International Bar Association Rules on the Taking of Evidence in International Arbitration (IBA Rules of Evidence, 2010) enjoy wide acceptance within the investor-State arbitral community. Indeed, it is commonplace that Procedural Order No. 1 (PO1) of any treaty arbitration incorporates an explicit reference to the IBA Rules of Evidence, often as a guideline for the tribunal.
The IBA Rules constitute a significant effort in harmonising the civil law and common law approach. They are intended to provide an “efficient, economical and fair process for the taking of evidence”, and “designed to supplement the legal provisions and the institutional, ad hoc or other rules that apply to the conduct of the arbitration."11
“Whenever the Parties have agreed or the Arbitral Tribunal has determined to apply [them], the [IBA] Rules shall govern the taking of evidence, except to the extent that any specific provision of them may be found to be in conflict with any mandatory provision of law determined to be applicable to the case.”12
B. Content of the IBA Rules of Evidence
Document Production (Article 3), the mandatory content of the Request to Produce (3.3), the reasons for objections to Documents requested (3.5, re 3.3 and 9.2), and confidentiality (3.13).
A commonly accepted tool for organizing document requests, objections, and decisions, is the Redfern Schedule (table with at least four columns). Regarding document production, it is also worthwhile to highlight as well the Armesto Schedule,14 a collaborative table inspired by the classic Redfern Schedule.
Witnesses of Fact (Article 4), including any person, including a Party or a Party’s officer, employee or other representative (4.2), the content of his or her Statement (4.5), and the consequences of failure to appear for testimony at an Evidentiary Hearing (4.7).
Party-Appointed Experts (Article 5), the mandatory content of the Expert Report (5.2, including “a statement regarding his or her present and past relationship with any of the Parties, their legal advisors and the Arbitral Tribunal, and a description of his or her background, qualifications, training and experience” (5.2.a); “a description of the instructions” received (5.2.b); “a statement of his or her independence” (5.2.c); “an affirmation of his or her genuine belief in the opinions expressed in the Expert Report” (5.2.g); and, “if the Expert Report has been signed by more than one person, an attribution of the entirety or specific parts of the Expert Report to each author” (5.2.i), Expert’s conference (5.4), and the consequences of failure to appear for testimony at an Evidentiary Hearing (5.5).
The Admissibility and Assessment of Evidence by the Arbitral Tribunal (Article 9), including: