Roger Federer has questioned why world No 1 tennis player Jannik Sinner was not suspended during the investigation into his two failed doping tests.

Ahead of Sinner’s US Open semi-final showdown with Britain’s Jack Draper on Friday, 20-time grand slam champion Federer said the controversy surrounding the Italian’s failed tests – which were kept quiet by the International Tennis Integrity Agency until he was cleared – is “noise that we don’t want” around the sport.

Sinner was allowed to continue competing until he was absolved of intentionally using an anabolic steroid he tested positive for twice in March.

“It’s not something we want to see in our sport, these types of news, regardless if he did something or not. Or any player did. It’s just noise that we don’t want,” Federer said on the Today show in the United States..

“I understand the frustration of: Has he been treated the same as others? And I think this is where it comes down to. We all trust pretty much at the end, he didn’t do anything.

“But the inconsistency, potentially, that he didn’t have to sit out while they were not 100 per cent sure what was going on – I think that’s the question here that needs to be answered.”

Hours later on Tuesday night, Federer received a warm ovation from spectators in Arthur Ashe Stadium when he was introduced to the crowd during the second set of the US Open quarter-final between Aryna Sabalenka and Zheng Qinwen.

Federer smiled and waved as he was shown on the videoboards in the arena.

It was the 20-time grand slam champion’s first visit to the venue since he stopped competing.

Following the ruling from the ITIA last month, Sinner said he wanted to put the “challenging and deeply unfortunate period” behind him.

“In my mind I know that I have done nothing wrong, which in this case helps a lot,” Sinner told Sky Sports ahead of the US Open, where he has so far encountered a warm welcome.

“Obviously you cannot control every single thing of the outcome of this case.”

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