The World Anti-Doping Agency (WADA) has appealed to the Court of Arbitration for Sport against an independent tribunal's decision in August to clear world number one tennis player Jannik Sinner after he failed a doping test.
WADA said on Saturday that the court's finding of "no fault or negligence" against the Italian was not in accordance with the current rules, and it would seek a "ban of between one and two years" for the Australian Open and US Open champion.
“In WADA’s view, a finding of no fault or negligence is incorrect under the current rules. WADA is seeking a period of ineligibility of between one and two years. WADA is not seeking to annul any results, except those already imposed by the trial court,” WADA said in a statement.
The tribunal, held by the International Tennis Integrity Authority (ITIA), accepted Sinner's explanation that the clostebol entered his body from a member of his support team through massage and physiotherapy.
Sinner, who beat Roman Safiullin to reach the quarter-finals of the China Open, said he was surprised by WADA's decision.
"We can't control everything, right? Obviously I'm very disappointed and surprised about this appeal, to be honest, because we've had three hearings. All three have been very positive for me," he said from Beijing.
"We're always talking about the same thing. Maybe they just wanted to make sure everything was in place. Yeah, I'm just surprised they appealed."
"The process was conducted in accordance with the guidelines of the World Anti-Doping Code; however, ITIA acknowledges and respects WADA's right to appeal the decision of the independent tribunal," ITIA said in a statement.
Sinner is the latest tennis player to be embroiled in a doping scandal after Simona Halep, but he has maintained his innocence, saying the amount of clostebol found in his system was less than one billionth of a gram.
He fired his coach and physiotherapist in August. He then hired a coach who had worked with Novak Djokovic.
Several players have criticised the court's ruling, including Britain's Tara Moore, who was sidelined for 19 months for failing a doping test before being cleared last year.
