Paris: The World Anti-Doping agency said Wednesday that it will not appeal against a three month ban imposed against China`s controversial double Olympic swimming champion Sun Yang but will warn China over the case.
WADA had considered action after Sun failed a doping test in May and was banned for three months by the Chinese federation but it was only announced in November after Sun had won more titles at the Asian Games.
"WADA has reviewed the full case file for the Chinese swimmer Sun Yang and has decided not to appeal the decision by the Chinese Swimming Federation to impose a three month sanction," WADA spokesman Ben Nichols told AFP in a statement.
"WADA has written to CHINADA however, raising its concern over the delayed public reporting of the case," the spokesman added.
Nichols said no other comment on the Sun case would be made.
The WADA code says violations must be publicly reported within 20 days and that decisions have to be sent to WADA in the same time-period.
The China Anti-Doping Agency (CHINADA) said it had been too busy with other cases to announce Sun`s suspension, despite his high profile.
The 1,500 metres world record-holder received his suspension in July but it was backdated to May, when he tested positive at China`s national championships for the stimulant trimetazidine.
Sun completed the unannounced ban on August 17 and in September, he starred with three gold medals at the Asian Games in Incheon, South Korea.
The case raised new suspicions about China`s doping stance. Australia barred Sun from training at one establishment. But Chinese officials insisted they handled the case properly.
Sun, 22, said after the test was announced that he was "shocked and depressed" over his positive test, which he maintains was an accident.
He told his doping hearing that he did not know the substance was banned, and that he took it as part of prescription medication for heart palpitations, according to state media.
Trimetazidine is currently banned in competition, but from January 1 will be downgraded and effectively no longer considered a banned stimulant.
Despite being a national hero, Sun has had several brushes with authority that has given him a wild child reputation.
He had a public falling out with a coach who said that a relationship with an airline flight attendant was distracting him from swimming.
Sun was banned from swimming for six months and briefly jailed after he was found to be driving without a licence. He was caught after his Porsche was hit by a bus.