SINGAPORE - The World Anti-Doping Agency may appeal to the Court of Arbitration for Sport after Chinese swimming star Sun Yang served a three-month doping ban in secret, a spokesman told AFP.
China's Sun Yang, pictured during the FINA World Championships, at Palau Sant Jordi in Barcelona, on August 4, 2013
The spokesman said WADA had not received full details of the case, while the World Anti-Doping Code says drugs violations must be made public within 20 days.
Chinese officials have denied covering up the suspension of the double Olympic champion, which took place between May and August but was only announced on Monday.
"WADA has not yet received the full decision regarding this case," the spokesman said via email, in response to questions sent by AFP.
"Once it is received, WADA will review the reasons for the decision and will subsequently decide whether or not to use its independent right of appeal to the Court of Arbitration for Sport."
Section 14.2.2 of the World Anti-Doping Code says violations must be publicly reported within 20 days and that decisions have to be sent to WADA in the same time-period.
Sun, 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.
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 China Anti-Doping Agency (CHINADA) said it had been too busy with other cases to announce Sun's suspension, despite his high profile.
"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 said Zhao Jia told Xinhua news agency.
"This is huge bad news but we will not cover it up."
- 'Outstanding athlete' -
Chinese swimming was notorious for doping in the 1990s but cases have become less frequent in recent years, while China has risen to prominence as a swimming power.
Ning Zetao was banned for a year in 2011 for taking the performance-enhancer clenbuterol. In September, he set an Asian 100m freestyle record of 47.70sec at the Asian Games.
Last year Li Zhesi, who was 14 when she anchored China to a 4x100m medley world record at the 2009 world championships, was banned for two years for taking the blood-booster EPO.
And China's top male backstroker Ouyang Kunpeng was banned for life by the Chinese Swimming Association over a positive drugs test in 2008, just before the Beijing Olympics.
China won just one swimming gold medal at the Beijing Games, while four years later Sun and a 16-year-old Ye Shiwen led them to a Chinese-record five wins at London 2012.
Ye attracted speculation after she took five seconds off her personal best in the 400m individual medley, and swam the last 50m of the final quicker than men's winner Ryan Lochte.
Sun, 22, told Xinhua he was "shocked and depressed" over his positive test for the banned stimulant trimetazidine, which he maintains was an accident.
He told his doping hearing that he didn't know the substance was banned, and that he took it as part of prescription medication for heart palpitations.
The Chinese Swimming Association on Tuesday defended Sun as an "outstanding athlete", while acknowledging he had "made some detours and had some tumbles".
Sun was briefly jailed last November for driving offences and barred from swimming for six months, and also last year he was suspended from commercial activities after a row with his coach over his relationship with an airline hostess.
The Olympic Council of Asia, which runs the Asian Games, told AFP it wouldn't take any action over the doping case of Sun, who won gold in the 1,500m, 400m and 4x100m freestyle in Incheon.