REUTERS | Kacper Pempel

Lagging behind: is there a clear set of rules for the treatment of illegally obtained evidence in international arbitrations?


Rightly or wrongly, applications to admit illegally or improperly obtained evidence (including evidence obtained by hacking) are on the rise in commercial disputes between private parties. The release of WikiLeaks diplomatic cables starting in 2010 resulted in parties seeking to introduce the confidential cables as evidence in investment treaty arbitrations, including the well-known RosInvestCo UK v Russian Federation case (Yukos awards). Unsurprisingly, these practices have now trickled down to international arbitration proceedings not involving state entities, where the leaked material has some bearing upon a private party’s commercial dispute with another private party.

A uniform approach?

There is little doubt that hacking attacks are on the rise. It is no longer just government entities or diplomatic missions that are targeted, but corporates and small businesses holding any level of confidential information that may be of use in an adversarial context. It would be safe to assume that as the number of hacking incidents increase, there will also be a commensurate rise in attempts to use such illegally or improperly obtained evidence in international arbitration proceedings.

Whilst tribunals in investment treaty arbitrations have tended to take a firmer approach to such applications, tribunals in international arbitration proceedings appear more willing to routinely admit into evidence documents leaked online. Nevertheless, there is no uniform or standard approach or test adopted by tribunals to determine whether or not to admit such evidence; the outcome therefore has the potential to vary widely from case to case. Is it time for the formulation of a standardised test?

At the Bergsten Lecture in Vienna earlier this year, Cherie Blair QC proposed a two-step admissibility test that takes account of:

  • The “clean hands” doctrine (whether the wrongdoing was by the party seeking to benefit from the evidence).
  • Public interest (whereby documents subject to privilege should always be inadmissible).

The current position: clean hands

The approach adopted by arbitral tribunals to the question of admitting into evidence illegally or improperly material has varied widely. From the notable Yukos awards (which relied heavily upon the evidence contained in WikiLeaks cables without addressing the issue of whether the documents in question were, or should be, admissible), to the ConocoPhilips v Venezuela case, tribunals have often demonstrated a reluctance to identify the principles (let alone any formal legal test) that may be relevant to determining the question.

One theme that emerges from a review of the case law is the question of whether the party seeking to introduce unlawfully obtained evidence into proceedings has played any part in procuring that evidence. Tribunals in investment treaty arbitrations have tended to take the approach that, if a party seeking to introduce the evidence participated in the unlawful activity that led to its disclosure, the evidence is inadmissible on the basis that a party should not be permitted to profit from its own misconduct (the “clean hands” doctrine). A notable exception is the 1949 Corfu Channel case between the United Kingdom and Albania, in which evidence unlawfully procured by the British Navy was admitted notwithstanding that the method of obtaining it was held to be a violation of Albanian sovereignty.

In Methanex Corporation v United States of America (which was an award made before the WikiLeaks cables were published), the tribunal declined to introduce into evidence materials that had been obtained by “successive and multiple acts of trespass committed by Methanex over five and half months”. The tribunal stated that to allow Methanex to introduce this documentation into the proceedings would be a violation of its general duty of good faith and offend against “the basic principles of justice and fairness required of all parties in every international arbitration”.

A similar approach was taken in the case of Libananco Holdings Co v Republic of Turkey, during the course of which Turkey intercepted around 2,000 of the claimant company’s privileged or confidential emails through government surveillance. A distinction in this case is that the surveillance undertaken by the Turkish government was not said to be unlawful; instead it was an exercise by the state of its sovereign right to counter criminal activity. Despite this, the tribunal weighed in favour of protecting a party’s privileged and confidential information by excluding the evidence from the arbitration proceedings.

The current position: privilege

In those cases in which a party has played no part in obtaining the leaked confidential information, arbitral tribunals often appear to base their decision on the question of privilege. Many international arbitration proceedings now incorporate the IBA Rules on the Taking of Evidence in International Arbitration 2010 (IBA Rules), which are designed to supplement the institutional or ad hoc procedural rules applying to an arbitration.

The relevant provisions of the IBA Rules relating to the admissibility of evidence are contained in Article 9, which states:

“2. The Arbitral Tribunal shall, at the request of a party or on its own motion, exclude from evidence or production any document, statement, oral testimony or inspection for any of the following reasons:

(b) legal impediment or privilege under the legal or ethical rules determined by the Arbitral Tribunal to be applicable;

(f) grounds of special political or institutional sensitivity (including evidence that has been classified as secret by a government or a public international institution) that the Arbitral Tribunal determines to be compelling.”

Article 9 of the IBA Rules was relied upon by the tribunal in the case of Caratube International Oil Company and Mr Devincci Saleh Hourani v Kazakhstan. Here, the claimant applied to admit into evidence leaked emails published on a WikiLeaks-type website, following a hacking attack against the Kazakh government’s computer network. Whilst the tribunal appreciated the need to protect against computer and cybercrime, and the potential unfairness of allowing confidential evidence obtained through hacking to be admitted, it also referred to the need for the tribunal to have access to information that is in the public domain, and allegedly relevant and material to the dispute. The tribunal held that, of the 11 documents to which the application related, any non-privileged leaked documents should be admitted, with the issues of authenticity and weight attached to the leaked documents to be resolved after they had been admitted in the proceedings.


Given the prevalence of parties seeking to introduce leaked confidential materials into evidence in international arbitration proceedings, it is questionable whether the current provisions of the IBA rules (read in conjunction with any institutional or ad hoc procedural rules applying to an arbitration) offer sufficient guidance to tribunals grappling with this complex topic. Clearly, there is a benefit, in particular in the arbitration context, in ensuring that procedural rules are not overly prescriptive. It is also arguable that considerations of public policy and government security are less relevant in commercial disputes between private parties, where the goal is for the tribunal to resolve the dispute at hand to the satisfaction of (hopefully) both parties. However, a standardised test (perhaps along the lines of the two-step test proposed by Cherie Blair QC), which could be applied in private disputes, would increase the certainty and transparency of awards on this issue.

Berwin Leighton Paisner Nikki O’Sullivan

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