[Source: Reuters]

World number one Jannik Sinner failed two drug tests in March but has been cleared of wrongdoing by an independent tribunal, the International Tennis Integrity Agency said on Tuesday days before the Italian is set to play at the U.S. Open.

The tribunal convened by Sport Resolutions accepted the Australian Open champion’s explanation that the anabolic agent clostebol entered his system from a member of his support team through massages and sports therapy.

Naldi was unaware that the product he had used on his cut contained clostebol, Sinner said. Clostebol is a steroid that can be used to build muscle mass.

Sinner’s first positive sample was taken on March 10 with a second eight days later. A provisional suspension was applied with each positive test but he was allowed to keep playing after his team filed urgent appeals.

WADA said it would review the decision and reserved the right to appeal.

Sinner, who has always maintained his innocence, said the amount of clostebol found in his system was less than a billionth of a gram.

Sinner is the latest tennis player to become embroiled in a doping case after twice major winner Simona Halep had her four-year doping ban cut to nine months this year after testing positive for a prohibited substance at the 2022 U.S. Open.

Halep argued she had unwittingly ingested the blood-booster roxadustat through contaminated nutritional supplements.

As the world’s top-ranked player, Sinner had already expected the spotlight to fall on him when he arrived in New York for the year’s final major that kicks off on Monday.

But the saga has invited an added layer of attention a day after he won a key U.S. Open tune-up event in Cincinnati.

Australian player Nick Kyrgios lambasted the Sinner ruling.

The U.S. Open main draw begins on Aug. 26.