With the expansion of international anti-doping regulations, the adjudication of doping-related violations has gained central importance before the Court of Arbitration for Sport (CAS). This paper examines the typology of evidence in CAS proceedings, with a particular focus on doping cases. As the leading global forum for resolving sports disputes, CAS has played a significant role in shaping the legal framework for combating doping in sport.

Using a descriptive-analytical method, this study analyzes the legal standards applied by CAS in assessing evidence and classifies the main types of evidence relied upon in doping-related disputes. These include laboratory results, Athlete Biological Passports (ABPs), expert testimony, and scientific reports. Due to the scientific and technical nature of these cases, the evidentiary process in doping disputes differs from other types of sports-related conflicts.
One distinctive feature is the application of the strict liability principle, under which the mere presence of a prohibited substance in an athlete's body constitutes a violation, regardless of intent or negligence. This principle shifts the evidentiary burden and has significant implications for how doping cases are adjudicated.In conclusion, the paper offers recommendations to strengthen procedural fairness and enhance the evidentiary framework in CAS doping proceedings. By focusing on an underexplored area in Persian-language legal scholarship, this research provides a clearer understanding of evidentiary practices in CAS and highlights their potential to inform future legal and institutional reforms in international sports law.