I. INTRODUCTION

Over the course of the last few decades, it has become the usual practice in international arbitration proceedings for the direct evidence (“evidence in chief”) of a witness to be reduced to writing and to be submitted in the form of a detailed witness statement prior to a hearing at which the witness may then be subject to examination.1

Although the use of such witness statements is now widely (if not universally) considered to be a standard practice in international arbitration, this has not always been the case. Not so many years ago, as recently as the 1980s and 1990s, there were many more international arbitrations than today in which witness statements of the kind now usually favored were not used. In some cases, the parties might have been invited by the arbitral tribunal to submit a list of topics on which they proposed to have their witnesses give evidence at the hearing and to identify the witnesses in question.2 In others, the parties might have been invited to submit a written summary of their witnesses’ intended testimony, without, however, having to produce detailed statements.