Chinese swimmer Sun Yang, who was accused by Doping Control Agency IDTM of refusing a drug test in 2018, was banned from competition for eight years by the Court of International Arbitration for Sport (CAS) for “interference with stimulant control”. After a second hearing, the CAS recently announced that Sun’s ban was reduced to four years and three months and that he would not compete in the Tokyo Olympics.
In fact, Chinese athletes have a long history of being exposed for taking banned drugs, with a peak in the 1990s. In 1990-1998, 28 Chinese swimmers tested positive for stimulants, accounting for half of the total number of world athletes who used banned drugs at that time.
History of Chinese Athletes Doping to Win | China Observer