Nick Kyrgios has backtracked from his claim the ATP is corrupt, accusing the governing body of men’s tennis of double standards instead. The ATP on Wednesday launched an investigation into Kyrgios’s sensational allegations, made after his US Open first-round win over Steve Johnson hours earlier.

The tennis firebrand was asked what he thought about being fined a record $US113,000 ($A167,000) for his spectacular meltdown in Cincinnati earlier this month.

US Open 2019 first round: Nick Kyrgios beats Steve Johnson in straight sets – as it happened Read more

“The ATP is pretty corrupt anyway. I’m not fussed about it at all,” he said. “I was fined 113,000 K for what? Why are we talking about something that happened three weeks ago when I just chopped up someone first round of a US Open? Have you ever sworn at someone before? You’re not an elite athlete ... I’m just saying people get frustrated. It happens.”

But, already considering also banning Kyrgios for his Cincinnati outburst – in which he called Irish umpire Fergus Murphy a “potato” and “fucking tool” – the ATP is again considering further punishment for the 24-year-old’s latest “major offence”.

“The comments made by Nick Kyrgios after his first round match in New York will be assessed under the player major offense provision under ATP Rules,” the ATP said in a statement. “A determination will be made by Gayle David Bradshaw, executive vice president, rules & competition, following an investigation as required by ATP rules.”

Shortly after the statement was released, Kyrgios took to social media “to clarify my comment around the ATP being corrupt”.

“It was not the correct choice of words and my point and intention was to address what I see as double standards rather than corruption,” he tweeted. “I know my behaviour at times has been controversial and that has landed me in trouble, which at times is granted and valid.

“But my issue is around others whether gaining the same, less or more media attention doing the same or similar behaviour and not being sanctioned. That’s my issue and it continues to be. To be clear I know I’m not perfect and do not pretend to be and I acknowledge I’ve deserved fines and sanctioning at times.

“But I expect consistency and fairness with this across the board, to date that’s not happened. I’ve had huge support from [ATP boss] Chris Kermode and have given it in return, so I want to clarify my comments but stand by my beliefs and sentiment around double standards.”

Whether Kyrgios’s explanation saves him remains to be seen. The 2019 ATP rule book says a “major offence” may be punished by a fine of up to the amount of prize money won at a tournament and a suspension of up to a year.

The two-time grand slam quarter-finalist has a long rap sheet stretching back four years. In May, Kyrgios was defaulted from a match at the Italian Open after throwing a chair across the court. He was suspended and ordered to undergo counselling after tanking at the 2016 Shanghai Masters.

The US Open is run independently but a USTA official told AAP pre-tournament that organisers of the New York slam would follow the ATP’s lead when asked if Kyrgios could be banned.

Kyrgios is due to face Frenchman Antoine Hoang on Thursday for a place in the last 32.