The case involves Russian heptathlete Tatyana Chernova, who won a bronze medal at the 2008 Beijing Olympics but was later disqualified due to an anti-doping rule violation. The International Olympic Committee (IOC) re-tested her urine samples as part of a broader re-analysis program and found evidence of Dehydrochlormethyltestosterone (Turinabol), a prohibited substance. The initial re-analysis of her A-sample indicated a potential violation, leading to a Presumptive Adverse Analytical Finding (PAAF). Chernova was notified and given the opportunity to attend the testing of her B-sample, which was split into B1 and B2 samples. She chose not to attend, and both samples confirmed the presence of Turinabol metabolites, resulting in an Adverse Analytical Finding (AAF). The IOC initiated disciplinary proceedings, offering Chernova a hearing before the Disciplinary Commission. She maintained her innocence but failed to provide sufficient evidence to challenge the laboratory findings. The Commission concluded she had committed an anti-doping violation and disqualified her results, including the withdrawal of her medal. Chernova appealed to the Court of Arbitration for Sport (CAS), arguing procedural flaws and questioning the reliability of the laboratory analysis. She contested the inclusion of unrelated evidence, such as the McLaren Report and a prior positive test, and raised concerns about inconsistencies between the B1 and B2 samples. The IOC defended its decision, asserting the laboratory complied with World Anti-Doping Agency (WADA) standards and that minor discrepancies did not invalidate the results. The CAS panel upheld the IOC’s decision, emphasizing the strict liability principle in anti-doping regulations, where the mere presence of a prohibited substance constitutes a violation. The panel found no evidence of procedural errors or flawed laboratory analysis, as both parties’ experts agreed the testing met WADA’s International Standard for Laboratories (ISL). Chernova’s appeal was dismissed, and the IOC’s sanctions remained in effect. The case underscores the challenges athletes face in contesting re-test results years after competition and highlights the importance of adhering to established laboratory protocols. The final ruling reaffirmed the integrity of anti-doping measures and the consequences of violations, regardless of intent or fault. The CAS award, issued on 4 December 2017, confirmed the disqualification of Chernova’s results and the forfeiture of her Olympic medal.