The World Anti-Doping Agency (WADA) has appealed to the Court of Arbitration for Sport (CAS) against an independent tribunal's decision in August to clear world No. 1 Jannik Sinner of wrongdoing after he failed drug tests, WADA said on Saturday.
WADA said the tribunal's finding of "no fault or negligence" on Sinner's part was incorrect under the applicable rules, and it would seek "a period of ineligibility of between one and two years" for the Australian Open and US Open champion.
The tribunal, organised by the International Tennis Integrity Agency, had accepted Sinner's explanation that the anabolic agent clostebol entered his system from a member of his support team through massages and sports therapy.
The ITIA said in a statement on Saturday: "The process was run according to World Anti-Doping Code guidelines; however, the ITIA acknowledges and respects WADA’s right to appeal the independent tribunal’s decision."
Sinner said his physio, Giacomo Naldi, applied an over-the-counter spray containing clostebol to his skin to treat a small finger wound and then administered massages between March 5 and 13 without using gloves, according to the ITIA.
Italy's Sinner has maintained his innocence, saying the amount of clostebol found in his system was less than a billionth of a gram. However, some players criticised the verdict, saying Sinner's explanation "made no sense."