Admissibility of Illegally Obtained Evidence: A Right From A Wrong?


While there are no bright-line tests that govern the admissibility of illegally obtained evidence, prior arbitral determinations (such as Caratube Case, Libanco Case) emphasize, whether the documents are confidential, whether the information revealed was relevant and material to the decision on the merits and whether either of the parties were involved in the procurement of the evidence. The following is to shed light on the ambivalent stances of various courts, tribunals and clear the air on the question of admissibility of illegally obtained evidence.


Arbitral tribunals across jurisdictions have the liberty to admit any evidence as they deem fit, determinable on a case to case basis. However, tribunals ought to exercise such power within the restrictive walls of the governing rules of procedure, i.e. lex arbitri. Amongst many arbitral institutions, the prominent ones are LCIA, AIAC, SIAC, VIAC, HKIAC. The rules administered by these institutions sufficiently provide for admissibility of evidence, yet, on the question of admissibility of illegally obtained evidence, none of them have a mouth to offer.

In the absence of explicit directives within the lex arbitri, the framework of IBA Rules is seminal. Notably, they do not exclude the admission of illegally obtained evidence but refer to “relevance to the case and materiality to its outcome” as the two decisive criteria for evidence to be admitted [Art 9(1)(a) IBA].

Before delving into the significance of illegally obtained evidence being relevant and material, it is of paramount importance that one understands the consequences of admittance of such evidence which essentially brings into light the perennial conflict between confidentiality and transparency.

The need for ensuring transparency in international dispute settlement systems arose with the introduction of UNCITRAL Rules of Transparency. These rules, applicable to investment disputes, harmonize the legal framework of efficient and fair adjudication, thereby increasing transparency and accountability in the process. Ideally, the same aspirational interest ought to extend to private commercial arbitration as well. Yet, substantial jurisprudence exists in international arena which holds a candid belief that such an extension is troublesome due to confidentiality, which is the cornerstone of commercial arbitration. (See Victoria Pernt’s How Much (More) Transparency Does Commercial Arbitration Really Need?).

Regardless, several national courts across jurisdictions have, in a quest to ensure transparency and judicial efficacy in commercial arbitration, permitted disclosure of confidential information. In the leading case of AAY v. AAZ, Singaporean High Court was compelled to make a prior arbitral award public, owing to imperative public interest considerations. Broadly, the need to exempt confidentiality arises in three situations: (1) where the documents are necessary for fair disposal of a case; (See Emmott v Michael) (2) where the information sought could only be obtained at the expense of confidentiality; (See Dolling-Baker Case) and (3) to avoid inconsistent findings, as a party to more than one arbitration will sometimes appoint the same arbitrator in all proceedings. (See Aquator Case).

Additionally, the veil of confidentiality may also be lifted in cases where the information is available to the public. (see Persia International Bank Case). This is based on the principle that a party should not be denied its right to submit information if everyone else has access to it. Such widespread dissemination of confidential information is not uncommon, especially after the Wikileaks scandal. Yet, the only drawback to this exception is that the term ‘public domain’ has not been accorded with a universal definition, thereby leaving enough room for varied interpretations by courts and tribunals. While the popular opinion post-Wikileaks is that information is in the public domain only when it is accessible through the World Wide Web, the other school of thought states that mere cognizance of information to the third party can cause the information to enter the realm of public domain.


In addition to the abovementioned, there may exist another situation where the bars of confidentiality may be lifted. This occurs precisely in cases where relevant and material evidence is obtained illegally. Admittedly, even though the popular notion is that confidentiality does not concern itself with admission of evidence, it is intrinsically related to the question of admission of illegally obtained evidence. This is because evidence which is illegal is, more often than not, obtained without the consent of the other party.

Contrary to the fallacious belief, the standards of relevance and materiality are distinct and independent of one another. While the evidence is relevant when it is useful to prove a fact from which a legal conclusion can be drawn, it is material if the information is needed for a complete consideration of the legal issues. Many arbitration institutions endorse this standard for admission of evidence in addition to the wide discretionary powers given to the arbitrators. However, this discretion cannot be negatively exercised if the evidence is of substantial probative value, irrespective of whether or not it is lawfully or unlawfully obtained. (See Conoco Phillips, Corfu Channel Case). This follows the practice of admitting the evidence and thereafter considering its weight, rather than excluding it from the outset.

Notwithstanding, the rule of relevance and materiality may be exempted if there is proof that the party submitting the information was directly involved in its illegal obtainment. (See Methanex Case). This exemption is derived from the fundamental notion that a right cannot stem from a wrong and that a party ought not reap the benefits of its own wrongdoing. It follows the principle of the so-called “Fruit of the Poisonous Tree Doctrine”. Pursuant to this doctrine, evidence cannot be admitted if it has any illegal roots. However, in international arbitration, arbitrators are qualified to decide the case in a fair manner and do not have to be ‘protected’ from illicit information, thereby not warranting such strict exclusionary doctrine. Holding the contrary would also be in contravention to the character of international arbitration of not limiting the parties’ right to submit evidence.


In conclusion, there is an international common understanding in favor of the admission of illegally obtained evidence. In international arbitration, contrary to the national laws, party autonomy is a cardinal principle following which the rules of procedure and guidelines governing the arbitral proceedings are at the option of the parties themselves. Therefore, illegally obtained evidence is admissible if it is relevant and material to the case, provided that the parties are not involved in an illegal procurement.

Devarakonda Venkata Sai Yasaschandra and Siddharth Jain are 3rd-year students at National Law University Odisha, Cuttack

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