The World Anti-Doping Agency (WADA) has confirmed it has appealed the decision to allow Jannik Sinner to continue playing professional tennis despite failing a drugs test. In a released statement, the authority argued that the initial finding of ‘no fault or negligence’ on Sinner’s part was incorrect.

In August, it was announced Sinner had received an anti-doping sanction and been stripped of his prizevmoney and ranking points from the Indian Wells Masters in March, due to testing positive for Clostebol.

“The World Anti-Doping Agency confirms that on Thursday 26 September, it lodged an appeal to the Court of Arbitration for Sport in the case of Italian tennis player Jannik Sinner,” they said in a statement released on Saturday 28th.

“Who was found by an independent tribunal of the International Tennis Integrity Agency to bear no fault or negligence having twice tested positive for clostebol, a prohibited substance, in March 2024.”

And in a warning that the 23-year-old could now be banned for as long as two years, they added: “It is WADA’s view that the finding of ‘no fault or negligence’ was not correct under the applicable rules. WADA is seeking a period of ineligibility of between one and two years.

“WADA is not seeking a disqualification of any results, save that which has already been imposed by the tribunal of first instance. As this matter is now pending before CAS, WADA will make no further comment at this time. “

It means that Sinner, who has since parted ways with Naldi, will still keep the Australian Open and US Open titles he won this year. However, the threat of a potential two-year suspension will worry the Italian and his team following a season that has seen him establish himself as the new world No.1

Sinner has admitted to receiving a frosty reception from fellow ATP Tour players since news of his failed test became public knowledge. And Nick Kyrgios has led a chorus of voices arguing he was given preferential treatement because of his superstar status.

But the two-time Grand Slam champion, who is currently competing in the China Open, has always insisted he is not guilty of wrongdoing. And he’s maintained he has adhered to anti-doping regulations throughout his career.

“In my mind, I know that I haven’t done anything wrong,” Sinner previously said. “I always respect these rules, and I always will respect these rules, of anti-doping.”

Sinner, the top seed in Beijing, won through to the quarter-finals on Thursday after coming through a tough test with Nicolas Jarry 4-6 6-3 6-1. That result set up a Saturday clash with Russian Roman Safiullin.