The Admissibility of Unlawfully Obtained Evidence before International Courts and Tribunals

70 years ago, the International Court of Justice decided its first and potentially most important case involving unlawfully obtained evidence. Despite clearly rejecting ‘discovery by intervention’, the judgment left many guessing as to the consequences for evidence obtained through such violations. As parties to international disputes have certainly not become less inclined to obtain evidence by unlawful means, the question arises: Was this old confusion ever unraveled? This article discusses whether today, there are international rules or principles governing the admissibility of unlawfully acquired evidence and applies a two-fold approach. First, it examines traditional sources of international law, including international jurisprudence, and second, it scrutinizes the frequently drawn analogy to national jurisdictions by surveying their treatment of illegally obtained evidence. Although a generally binding “inadmissibility rule” does not yet exist, practice demonstrates a tendency to consider such evidence in light of general principles of law. This article proposes handling unlawfully acquired evidence by applying a defined, yet flexible balancing test using criteria commonly applied in international and national practice.

Excluding evidence (or staying proceedings) to vindicate rights in Irish and English law

The constitutional duty of the Irish state ‘to defend and vindicate the personal rights of the citizen’ is the basis of a strict rule excluding unconstitutionally obtained evidence. Although English courts recognise a similar duty to ‘vindicate human rights and the rule of law’, their powers to exclude evidence or stay proceedings for abuse of process are extremely flexible and discretionary. In both jurisdictions, there has been particular controversy over the application of these powers to covert recordings that breach legal professional privilege. This paper argues that the duty to vindicate rights and the rule of law underpins both the exclusion of unlawfully obtained evidence and the punishment of offenders. It requires a balancing exercise, not between defendants' rights and an incommensurable public interest but, rather, between two aspects of the same constitutional duty of the courts.