According to the US Anti-Doping Agency, sprinter Erriyon Knighton tested positive for the performance enhancer trenbolone during an out-of-competition test in March. Later, in June, USADA contended that the trenbolone in his sample came from contaminated meat, while clearing him for the Paris Olympics.

Knighton, who holds the under-18 and under-20 records in 200 meters, is a favorite to add to the US' medals tally.

Certain US media outlets turning a blind eye to this case have accused the China Anti-Doping Agency and WADA of "covering-up" a 2021 food contamination case, that had long been cleared, against some Chinese swimmers competing in Paris. The double standard displayed by US agencies and media outlets on doping issues could not be clearer.

On Tuesday, while meeting the US Olympic& Paralympic Committee Chair Gene Sykes, the Chinese Olympic Committee President Gao Zhidan urged the US side to honor its promise of stopping "long-arm jurisdiction" so that Chinese athletes and their counterparts from elsewhere can participate in the races smoothly.

The US also shields its players from doping allegations by giving the excuse of diseases. According to a Global Times report, in 2015 some 653 US athletes applied to WADA for an "exemption" as they were "taking medication for some illness". So many members of the US swimming team are on "medication" for asthma that some jokingly call it the "US asthma team".