CNA Explains: China's swimming doping scandal – is politics involved?

SINGAPORE: With three months to the Paris Olympics, the sporting world has been hit with revelations that 23 Chinese swimmers took a banned drug ahead of the last Games in 2021 – and were allowed to compete anyway. 

Here’s a breakdown of what happened and why.

It was reported that the athletes tested positive for a prescription heart drug, trimetazidine (TMZ) – which can enhance performance – at a domestic meet in late 2020 and in the early days of 2021. The Tokyo Olympics were held in July and August 2021.

TMZ has been on the World Anti-Doping Agency's (WADA) list of banned substances since 2014, and is prohibited for use in and out of competitions. 

Quoting Dr Kelly Johnson-Arbor, a medical toxicology physician at MedStar Georgetown University Hospital, Reuters reported that TMZ could "theoretically” help an athlete’s heart function better if they’re competing in a highly exertional sport, where a lot of energy is used and the heart is put under significant stress. 

According to Chinese investigators, trace amounts of TMZ were found in the kitchen of a hotel where the athletes were staying. 

WADA was notified in June 2021 that Chinese anti-doping authorities had accepted that the swimmers had tested positive for TMZ after “inadvertently being exposed to the substance through contamination”. 

In reviewing this, WADA consulted with independent scientific experts to test the contamination theory, as well as whether low doses of the drug could have benefited the athletes during competition. 

WADA ultimately concluded that it was "not in a position to disprove the possibility that contamination was the source of TMZ”. 

WADA and swimming's governing body World Aquatics decided not to take action due to "a lack of any credible