Wada calls for long ban for Jannik Sinner, world number 1, because of positive drug tests | Jannik Sinner

World No. 1 Jannik Sinner faces another ban after the World Anti-Doping Agency (Wada) appealed a verdict of “no fault or negligence” over two positive tests he returned in March .

Sinner, who won the US Open earlier this month, tested positive for an anabolic steroid twice in March, but on August 20 the International Tennis Integrity Agency (ITIA) found he was not at fault and imposed no penalty.

The ITIA accepted Sinner's explanation that the banned substance entered his body through a massage from his physiotherapist, who had used a spray containing the steroid to treat a cut on his finger. But Wada has appealed to the International Court of Arbitration for Sport (CAS) and asked that the 23-year-old Italian be banned for up to two years.

A statement from the agency said: “Wada is of the opinion that the finding of 'no fault or negligence' was incorrect under current regulations.” Wada is requesting a ban of between one and two years. Wada does not seek annulment of any results, except those already imposed by the Court of First Instance.”

The ITIA said in a statement on Saturday: “The trial was conducted in accordance with the guidelines of the World Anti-Doping Code; However, ITIA recognizes and respects Wada’s right to appeal the decision of the independent tribunal.”

Sinner said his physical therapist, Giacomo Naldi, applied an over-the-counter spray containing Clostebol to his skin to treat a small finger wound and then performed massages without wearing gloves between March 5 and March 13, according to the ITIA.

Italy's Sinner maintains his innocence, saying the amount of Clostebol found in his body was less than a billionth of a gram. However, some players criticized the verdict, saying Sinner's explanation “makes no sense.”