It is common to use witness statements in international arbitration. The witness can typically be any person including officers, representatives or employees of the party for which he/she is to provide testimony. The reasons to use witnesses in international arbitration are multiple: to reinforce evidence already presented in support of a party’s claim(s), to “fill” an evidentiary gap when other evidence is insufficient or ambiguous, or to rebut evidence presented by the other party.
The intervention of witnesses is commonly done through the submission of written witness statements, which are often submitted along with the parties’ written submissions. If one party submits a witness statement with its written submission, the other party will have an opportunity to comment upon it in its subsequent submission or to present a rebuttal witness statement. Having a witness statement submitted along with written submissions will allow the arbitral tribunal, as well as the parties, to prepare for the evidentiary hearing during which, if called, the witnesses are to be examined and questioned regarding the content of their statements.
In some cases, the appearance of a witness can also be ordered directly by the arbitral tribunal.
Structure of Witness Statements in International Arbitration
Although there are no mandatory requirements as to what form a witness statement should take, guidance is often sought in the IBA Rules on the Taking of Evidence in International Arbitration (“IBA Rules”). Pursuant to these rules, witness statements usually follow a common structure divided into several parts. We will discuss these parts in the sections below.
Introduction of the Witness
Article 4(5)(a) of the IBA Rules provides that the introduction of a witness shall contain:
“the full name and address of the witness, a statement regarding his or her present and past relationship (if any) with any of the Parties, and a description of his or her background, qualifications, training and experience, if such a description may be relevant to the dispute or to the contents of the statement.”
The introductory part permits identification of the witness, his/her educational or professional background, as well as his/her ties to the parties. If the relationship of the witness and the party who relies on his/her testimony is not apparent, it is recommended to clarify the matter in order to diminish surprises which can occur during the examination of the witness at a hearing. In fact, “not disclosing an existing or prior relationship between the witness and a party may appear as an attempt to conceal potential sources of bias”. To complete identification and background, the witness’s résumé is usually attached to his/her first witness statement.
Statement of Facts
Article 4(5)(b) of the IBA Rules provides that a witness statement shall contain “a full and detailed description of the facts, and the source of the witness’s information as to those facts, sufficient to serve as that witness evidence in the matter in dispute. Documents on which the witness relies that have not already been submitted shall be provided.”
The full and detailed description of facts represents the core of the witness statement. In this part, the witness will provide his or her recollection of certain facts. Although the IBA Rules use the term “full and detailed”, no indication is given as to the extent to which a presentation of facts is to be regarded as full and detailed. As pointed out by Ragnar Harbst, discrepancies in the length and detail of witness statements submitted by the parties can be problematic and undermine a level playing field. He stresses that “[i]f only one side offers detailed witness statement, only the other side can prepare. On the other hand, the party offering only a short and superficial witness statement also runs a risk. A strict arbitral tribunal may only grant limited room for the witness to add further facts and details during the hearing.” Therefore, although providing short and perfunctory witness statements can be appealing from a strategic standpoint, one should bear in mind that such a strategy can backfire since the witness, or the party for which the witness is giving testimony, may be prevented to rely on further evidence at subsequent stages of the procedure.
Sometimes indications as to the length and detail of witness statements are given by the arbitral tribunal itself. For example, in Appendix IV of the 2021 ICC Arbitration Rules, several case management techniques to control time and costs are envisaged. For instance, the arbitral tribunal can limit “the length and scope of written submissions and written and oral witness evidence (both fact witnesses and experts) so as to avoid repetition and maintain a focus on key issues.”
Statement as to the Language
Article 4(5)(c) of the IBA Rules provides that a witness statement shall include “a statement as to the language in which the Witness Statement was originally prepared and the language in which the witness anticipates giving testimony at the Evidentiary Hearing.”
This is particularly important in arbitrations which are held in a specific language, e.g., often English, but involve parties or witnesses who are not fluent or native in that language. Therefore, it is recommended to clarify this matter in the witness statement, so that an interpreter can be secured for the final hearing in case of need.
Affirmation of Truth and Signature
Article 4(5)(d) of the IBA Rules specifies that a witness statement shall contain “an affirmation of the truth of the Witness Statement”. In turn, Article 4(5)(e) requires a witness statement to include “the signature of the witness and its date and place.”
There is no imposed form regarding the affirmation of truth. It can consist of simple declarations; such as: “I, [name of the witness], hereby affirm that the contents of this Witness Statement are true and correct to the best of my knowledge and belief” or “I, [name of the witness], believe that the facts stated in this Witness Statement are true.”
Witness Statement Drafting
There are several tips to write a credible and comprehensible witness statement:
- A witness statement is a personal declaration of its author containing his/her recollection of the facts. Therefore, it should be written in the first person singular.
- Unless the witness is a lawyer or has a legal background, he/she should abstain from using legalese. Several examples of legalese were helpfully summarized by Ragnar Harbst in his treatise on Witness Preparation in International Arbitration as follows:
- The content of a witness statement should be clear, precise and structured under proper headings. Such headings can be divided, for instance, chronologically or subject-matter wise.
To What Extent Can a Lawyer Intervene in Drafting Witness Statements in International Arbitration?
To this thorny question, Article 4(3) of the IBA Rules responds that “[i]t shall not be improper for a Party, its officers, employees, legal advisors or other representatives to interview its witnesses or potential witnesses and to discuss their prospective testimony with them.” In turn, the IBA Guidelines on Party Representation in International Arbitration, and namely Guidelines 20 and 21, further specify that “[a] Party representative may assist Witnesses in the preparation of Witness Statements [and] should seek to ensure that a Witness Statement reflects the Witness’s own account of relevant facts, events and circumstances.”
Unless the law of the seat of arbitration provides otherwise, the role of the counsel is, thus, limited to assistance. The counsel is not prevented from discussing a witness statement with the witness. Also, as an arbitration professional, the counsel should know best how witness statements should be structured and can guide the witness in this respect. However, what is not allowed is for the counsel to write the witness statement, i.e., “write down what the witness might, could, or should say, and then ask the witness to confirm the same.”
 See IBA Rules on the Taking of Evidence in International Arbitration, Article 4(2): “Any person may present evidence as a witness, including a Party or a Party’s officer, employee or other representative.”
 See IBA Rules on the Taking of Evidence in International Arbitration, Article 4(10): “At any time before the arbitration is concluded, the Arbitral Tribunal may order any Party to provide for, or to use its best efforts to provide for, the appearance for testimony at an Evidentiary Hearing of any person, including one whose testimony has not yet been offered. A Party to whom such a request is addressed may object for any of the reasons set forth in Article 9.2.”
 R. Harbst, “A Counsel’s Guide to Examining and Preparing Witnesses in International Arbitration”, Wolters Kluwer (2015), p. 70.
 R. Harbst, “A Counsel’s Guide to Examining and Preparing Witnesses in International Arbitration”, Wolters Kluwer (2015), p. 71.
 R. Harbst, “A Counsel’s Guide to Examining and Preparing Witnesses in International Arbitration”, Wolters Kluwer (2015), p. 84.
 R. Harbst, “A Counsel’s Guide to Examining and Preparing Witnesses in International Arbitration”, Wolters Kluwer (2015), p. 74.