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Nearly every arbitration involves the taking of evidence. The applicable procedures affect what evidence is introduced and how. This can, and often is, outcome determinative. Thus, procedural questions around the process for taking evidence are some of the most common and the most important in arbitration.

This book draws together a group of highly experienced practitioners who address the topic from both theoretical and practical perspectives. Although the first edition was timed to reflect the 2020 amendments to the International Bar Association’s Rules on the Taking of Evidence in International Arbitration (the IBA Rules), the book is not intended to be another commentary to the IBA Rules.[2] Rather, following in the tradition of some older publications,[3] this book addresses the topic from a number of perspectives. The Rules on the Efficient Conduct of Proceedings in International Arbitration (the Prague Rules), published in 2018, have become an important counterpoint to the IBA Rules, and we have sought to include a wide variety of civil and common law viewpoints.

The book starts with a series of chapters providing high-level perspectives on the taking of evidence in international arbitration. In Chapter 1, ‘Approaches to Evidence across Legal Cultures’, James Hope and Marcus Eklund take a bird’s-eye perspective, situating the taking of evidence in the wider context of various legal traditions.

In Chapter 2, ‘The 2020 IBA Rules on the Taking of Evidence in International Arbitration: A History and Discussion of the 2020 Revisions’, Joseph Neuhaus, Andrew Finn and David Blackman introduce the 2020 IBA Rules, both the paths taken and certain proposals that were deliberated by the IBA Rules Subcommittee but ultimately rejected. Joseph Neuhaus co-chaired the Guidelines and Rules Subcommittee tasked with the 2020 revisions, and David Blackman was one of the secretaries on the task force that proposed the revisions. Key changes included the addition of provisions on the taking of evidence in remote hearings, the inclusion of cybersecurity and data protection issues in the remit of the Article 2 consultation, and the introduction of new grounds for objections, namely to the production of evidence from third parties or to evidence procured by corrupt means.

In Chapter 3, ‘The Prague Rules: Fresh Prospects for Designing a Bespoke Process’, Janet Walker takes stock five years after the release of the Rules on the Efficient Conduct of Proceedings in International Arbitration in 2018. She applies a dual perspective, assessing both the intention behind a provision and how it may be perceived or misperceived by common law counsel. She concludes that the Prague Rules provide a number of fresh prospects for designing a bespoke arbitral process. She encourages practitioners to look beyond what may be initial misgivings and apply procedures that are suggested by those Rules, such as early assessment by the tribunal, greater restraint in document disclosure, assessing the need for witness statements by first evaluating summaries of the proposed testimony, joint commissioning of experts and tribunal-led settlement discussions.

In Chapter 4, ‘Party and Counsel Ethics in the Taking of Evidence’, Amy Kläsener and Courtney Lotfi address ethical issues in connection with taking evidence. They review approaches to counsel ethics in taking evidence under national laws and various ethical canons that can be applied in arbitration, including the International Council of Commercial Arbitration’s 2021 Guidelines on Standards of Practice in International Arbitration, the 2018 Prague Rules, the 2010 and 2020 IBA Rules, the London Court of International Arbitration’s 2014 and 2021 Rules, the IBA’s 2013 Guidelines on Counsel Representation and the International Law Association’s Hague Principles on Ethical Standards for Counsel Appearing before International Courts and Tribunals of 2010. The authors conclude that ethical problems and disputes can be best prevented by means of active discussion of ethical issues in case management conferences and inclusion of specific rules and requirements in procedural orders.

In Chapter 5, ‘Approaches to Managing Evidence as Criteria for Selecting Arbitrators’, Michael McIlwrath considers the all-important question of whether and how to consider styles for the taking of evidence in the selection of arbitrators. He helpfully provides a list of specific issues to consider, including, in particular, whether it is strategic to ‘domesticate’ the procedure for taking evidence. Finally, he provides guidance on how to discern different styles in arbitrator candidates, including through appropriate interviews, arbitrators’ self-disclosures and databases on the subject.

The next two chapters address practice tips for the taking of evidence. In Chapter 6, ‘Planning and Organising Effective Procedures for Taking Evidence’, Beata Gessel-Kalinowska vel Kalisz, Joanna Kisielińska-Garncarek, Barbara Tomczyk and Łukasz Ostas explore options for tailoring the procedure to the needs of the case. The authors discuss from a high-level perspective the various categories of evidence and common procedures for introducing and managing them in arbitral proceedings. In Chapter 7, ‘Evidentiary Objections’, Cinzia Catelli and Romana Weinöhrl-Brüggemann provide detailed guidance on the various grounds for objecting to requests for production of documentary evidence, witness questions or the admissibility of evidence more generally.

In Chapter 8, ‘Standards of Proof and Requirements for Evidence in Special Situations’, Michael Hwang and Clarissa Chern take on the more abstract, but very important, topic of standards and burden of proof. The special situations they consider include prima facie evidence and the switching of the burden of proof, allegations of fraud and corruption, and the use of estimations to prove damages.

In Chapter 9, ‘Perspectives on Document Disclosure’, Damián Vallejo and Esther Romay offer their views on what is probably the most controversial topic in evidence: document requests. They encourage the international arbitration community to draw from diverse legal traditions to mitigate unintended side effects of this mechanism and craft balanced solutions that work in an international context.

The next two chapters address the rapidly developing topics associated with electronic evidence. In Chapter 10, ‘Using Technology and e-Disclosure’, Julia Sherman, Himmy Lui, Kelly Renehan and Anish Patel explain how electronic evidence is handled in the United States and the United Kingdom, drawing on these regimes and on their experience in recommending best practices for managing electronic evidence in arbitration. In Chapter 11, ‘Managing Data Privacy and Cybersecurity Issues’, Erik Schäfer explains specifically what participants in the arbitral process need to know about these increasingly important issues. He provides practical suggestions, including a list of issues to address and proposed wording for procedural orders.

In Chapter 12, ‘Best Practices for Presenting Quantum Evidence’, Laura Hardin and Trevor Dick provide insights and best practice tips from quantum experts to counsel. These range from careful drafting of the expert’s instructions to preserving the independence of the expert, and ensuring that experts stay within their expertise, in particular when multiple experts may address related issues. The authors also address the preparation of persuasive reports and of useful joint statements, and effective presentation at hearings, including online hearings.

In Chapter 13, Stefan Riegler, Oleg Temnikov and Venus Valentina Wong address ‘Special Issues Arising when Taking Evidence from State Parties’. The involvement of state parties can create asymmetries in terms of access to information. The authors explore how objections raised by state parties, including those based on special political or institutional sensitivity, play out in practice. They also address the introduction of evidence that has been obtained illegally (for example, through leaks) and how both state and commercial parties use this evidence.

In Chapter 14, ‘Special Mechanisms for Obtaining Evidence’, Anna Masser, Lucia Raimanová, Kendall Pauley and Peter Plachý provide a clear overview of the recent developments in respect of Section 1782 of Title 28 of the US Code for harnessing US discovery in relation to foreign arbitrations. They also address the less well-known tool of freedom of information act requests under national legislation and international law. This mechanism can be a powerful tool for gathering evidence on state parties or in relation to regulated parties. They also address data subject access requests pursuant to EU rules on data protection and reliance on documents obtained in criminal proceedings.

Finally, in Chapter 15, ‘Artificial Intelligence in Arbitration: Evidentiary Issues and Prospects’, Martin Magál, Katrina Limond and Alexander Calthrop consider how artificial intelligence (AI) may impact the taking of evidence. They look first at AI’s potential role in claim development, the preparation of pleadings, the intelligent searching of documents, real-time analysis of an oral hearing and the prospect of AI-generated evidence. They then embark on an analysis of the limitations and potential risks of using AI to handle evidence in arbitration.

We are very grateful to all the authors for their valuable contributions and hope that this book proves to be an accessible and useful resource for a broad group of international practitioners and parties.


[1] Amy C Kläsener is a partner at Jones Day, Martin Magál is a partner at Allen & Overy Bratislava, s.r.o. and Joseph E Neuhaus is of counsel at Sullivan & Cromwell LLP.

[2] See, e.g., Nathan D O’Malley, Rules of Evidence in International Arbitration: An Annotated Guide (2nd edition, Routledge, 2019); Roman Khodzkin, Carol Mulcahy and Nicholas Fletcher (eds), A Guide to the IBA Rules on the Taking of Evidence in International Arbitration (Oxford University Press, 2019); Peter Ashford, The IBA Rules on the Taking of Evidence in International Arbitration: A Guide (Cambridge University Press, 2013); Tobias Zuberbühler, Dieter Hofmann, Christian Oetker and Thomas Rohner (eds), IBA Rules of Evidence: Commentary on the IBA Rules on the Taking of Evidence in International Arbitration (Schulthess, 2012).

[3] Frédéric G Sourgens, Kabir Duggal and Ian A Laird, Evidence in International Investment Arbitration (Oxford University Press, 2018); Jeffrey Waincymer, Procedure and Evidence in International Arbitration (Kluwer, 2012); Magnum Y W Ng, Evidence in Arbitration: The Law and Practice on Taking of Evidence in International Arbitration Proceedings: An Eclectic Approach of Common Law and Civil Law Systems (VDM, 2009); Teresa Giovannini and Alexis Mourre, Written Evidence and Discovery in International Arbitration: New Issues and Tendencies (ICC Institute, Dossier VI, 2009); Laurent Lévy and V V Veeder, Arbitration and Oral Evidence (ICC Institute, Dossier II, 2004); Peter V Eijsvogel, Evidence in International Arbitration Proceedings (Kluwer, 2001).

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