Reigning Australian Open and US Open champion, Jannik Sinner who won his seventh title of the season in Shanghai on Sunday, tested positive for clostebol in March.
An independent panel, which was presented the case by the International Tennis Integrity Agency,ITIA, accepted there was “no fault or negligence” attached to 23-year-old Sinner.
It said the world number one had provided a “credible” explanation and he was able to continue playing.
But the decision that Sinner bore no fault has been challenged by the World Anti-Doping Agency (Wada), which has launched an appeal to the Court of Arbitration for Sport (Cas).
No date has been set for the hearing.
“Whatever’s going to happen, I just wish for it to be resolved as soon as possible,” 24-time major champion Novak Djokovic said.
“This whole case is not helping our sport at all.”
However, Wada is seeking a ban of between one and two years for Sinner to be applied from the date of a Cas ruling.
Wada is an overarching independent body which produces the World Anti-Doping Code and ensures it is properly implemented.
In tennis, the ITIA applies the rules set out by Wada. It is the first time Wada has launched an appeal against a case led by the ITIA.
In the Sinner case, Wada believes the finding that the player held no fault or negligence is “not correct under the applicable rules”.
Sinner did not dispute traces of clostebol were found in his urine test and Wada is not questioning his explanation of why the substance ended up in his system.
But it does believe the player must take a portion of the responsibility