Between Advocacy and Neutrality: Role of Legal Expert Witnesses in International Construction Disputes

International construction disputes frequently involve overlapping jurisdictions, complex legal frameworks, and multifaceted contractual arrangements, posing significant challenges for tribunals in reaching fair and informed decisions. This study examines the role and influence of legal expert witnesses, particularly in construction disputes, through a structured, multistep desktop research methodology. It is guided by two principal objectives: first, to investigate the diverse roles of legal expert witnesses and the significance of their contributions in proving foreign law; and second, to investigate the factors influencing tribunals’ acceptance of legal expert testimony, including the clarity and coherence of such testimony, and credibility concerns relating to the appointing entity, specifically whether tribunals should rely on party-appointed legal experts or whether such concerns render tribunal-appointed experts preferable. The findings indicate that legal experts play a pivotal role in interpreting foreign law, clarifying contractual ambiguities, and providing evidential bases for a tribunal’s determination. However, tribunals’ reliance on expert testimony is conditional on its perceived clarity of testimony as well as the credibility and neutrality of the expert. While party-appointed experts promote adversarial rigor and party autonomy, tribunal-appointed experts enhance independence and institutional confidence. The study concludes that a balanced or hybrid approach provides the most effective mechanism for proving foreign law in international construction disputes. The study further offers recommendations aimed at strengthening the effectiveness, reliability, and legitimacy of legal expert evidence.