Olympic and world champion swimmer Sun Yang served a three-month ban earlier this year after testing positive for a banned stimulant, China’s anti-doping agency disclosed Monday. The official anti-doping agency said Sun, who won two golds at the London Olympics and holds the world record in the 1500m freestyle tested positive for trimetazidine in a test conducted on May 17 during China’s national swimming championships in Hangzhou.

The suspension began immediately and ended on Aug. 17, prior to Sun’s appearance in September at the Asian Games at Incheon, South Korea, where he won three gold medals.

The agency’s director, Zhao Jian, said the ban was only announced Monday as part of a periodic release of testing results and disciplinary measures. He said Yang’s support team and team doctor were also given unspecified penalties. “We usually report the violations quarterly or bi-quarterly and we have to wait until the handling of a particular case has been finished,” Zhao said.

Zhao said Sun waived his right to have his “B” sample tested, but defended himself at a July hearing by saying it was an ingredient in medication he was taking to treat a heart condition and he wasn’t aware it was banned. Trimetazidine was added to the World Anti-Doping Agency’s list of banned substances in January.

‘No cover-up’

Chinese doping officials say they were not trying to cover up Sun Yang’s positive test and that they held back news of his three-month suspension because they did not want to make any mistakes with “the most famous athlete in China”.

“Sun is the most famous athlete in China and is known in the world, which means we need to handle his case very cautiously,” CHINADA deputy director Zhao Jian told the country’s official Xinhua news agency. “This is huge bad news but we will not cover it up.