The World Anti-Doping Agency (WADA) has verified reports indicating that 23 Chinese swimmers tested positive for a banned substance before the 2020 Tokyo Olympics. The substance in question, trimetazidine (TMZ), which is commonly found in heart medication, was detected months prior to the Games. However, WADA has accepted China’s explanation that the positive tests were due to contamination.

The Chinese anti-doping agency (CHINADA) and the Chinese Swimming Association have not yet responded to requests for comment from Reuters regarding these findings. WADA was informed in June 2021 of CHINADA’s decision to attribute the positive tests to inadvertent exposure to the drug through contamination.

After reviewing the case and consulting with scientific experts and legal counsel, WADA concluded that it could not refute the possibility of contamination being the source of TMZ. Consequently, the athletes involved were deemed to have no fault or negligence, and WADA decided against appealing the ruling.

China’s swimming team, comprised of 30 members, achieved success at the Tokyo Games, winning six medals, including three golds. Despite these positive outcomes, the recent revelations of positive drug tests could cast a shadow over China’s performance and lead to increased scrutiny ahead of the upcoming Paris Olympics.

Notably, TMZ has been at the center of high-profile doping cases in China before. Olympic gold medalist Sun Yang received a three-month suspension in 2014 after testing positive for the drug. Similarly, several Chinese swimmers have been embroiled in doping controversies in past Olympic Games, highlighting ongoing challenges in the realm of anti-doping efforts.

In response to these developments, World Aquatics, the global governing body for aquatic sports, expressed confidence in the handling of the positive tests, affirming that they were conducted diligently and in accordance with anti-doping regulations. However, the news underscores the importance of vigilance and adherence to strict anti-doping protocols in the lead-up to major international sporting events.