BEIJING - The World Anti-Doping Agency may appeal to the Court of Arbitration for Sport after Chinese swimmer Sun Yang served a three-month doping ban in secret, according to an AFP report on Wednesday.

A WADA spokesman told AFP that 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.

"WADA has not yet received the full decision regarding this case," the spokesman said via email to 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."

Sun Yang had failed a doping test and been banned for three months, China Anti-Doping Agency (CHINADA) announced on Monday.

The star swimmer tested positive for stimulant trimetazidine on May 17 during the national championships.