Adverse Inference in International Commercial Arbitration

Abstract
Adverse inference is one of the most significant evidentiary tools in international commercial arbitration, playing an effective role in uncovering the truth and balancing the rights and obligations of the parties when faced with a party’s refusal or failure to produce documents, information, or other relevant evidence. Despite its practical importance, the scope and conditions for applying this concept vary across different legal systems and international arbitration rules, remaining a subject of debate in arbitral practice. The main research question addresses under what circumstances international arbitrators are permitted to draw a adverse inference from a party’s lack of cooperation in producing evidence, and to what extent this discretion aligns with the principles of fair trial, equality of arms, and the burden of proof. This study employs a descriptive-analytical method, examining the foundations, conditions, and effects of negative inference by utilizing international arbitration rules, arbitral practice (particularly the Iran-US Claims Tribunal), doctrinal views, and analyzing its relationship with the principle of good faith, party cooperation, and case management regarding evidence. The findings indicate that while negative inference does not substitute for evidence nor serve as a mechanism for shifting the burden of proof, it can function as a valid presumption—alongside other evidence—to significantly persuade the tribunal’s conscience and establish the facts. This occurs provided that the duty to produce evidence is established, the refusing party had access to the evidence, there is a material connection between the evidence and the dispute, and there is no justifiable excuse for non-production. Consequently, preventing abuse of the evidentiary process, negative inference contributes to enhancing efficiency, fairness, and justice in international commercial arbitration.