Introduction

4.01 The general preference for documentary evidence notwithstanding, fact witnesses are often relied on in international arbitration as a means of presenting evidence. The procedures for taking witness testimony have evolved over time and it would seem that the modern practice for admitting witness evidence follows three basic assumptions: (1) a party has the right to be given notice of the identity of a witness and the subject matter of their testimony-in-chief before a hearing; (2) a witness who has provided testimony should be available to answer questions of the opposing party and/or the tribunal based upon that testimony; and (3) a tribunal’s right to freely consider and weigh the evidence before it means that there are very few restrictions on who may offer testimony as a witness.