Australian Nick Kyrgios said it was "not the correct choice of words" to claim the ATP was corrupt but said it was guilty of double standards.
The world number 30 clarified the comments he made on Tuesday after he was asked about the $113,000 (£92,580) fine for his behaviour at the Cincinnati Masters earlier in August.
"I acknowledge I've deserved fines and sanctioning at times," Kyrgios tweeted.
"But I expect consistency and fairness with this across the board."
Following his US Open first-round win over Steve Johnson, the 24-year-old was asked whether he had been affected by the fine and responded: "Not at all. The ATP is pretty corrupt anyway, so I'm not fussed about it at all."
In Wednesday's follow-up statement, he said: "It was not the correct choice of words and my point and intention was to address what I saw as double standards rather than corruption.
"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."
There were five separate incidents of unsportsmanlike conduct during August'd Cincinnati third-round defeat by Karen Khachanov, during which the Australian swore at umpire Fergus Murphy.
Kyrgios walked off court against the wishes of Murphy after losing the second set. He also slammed two racquets on the floor in a corridor and in the third set engaged in repeated disputes with the umpire.
The ATP is yet to decide whether he has committed a "major offence" in making those initial comments, which could lead to a further fine or suspension.
Regarding the claims made by Kyrgios on Tuesday, the governing body said they will be "assessed under the player major offence provision under ATP rules".
The statement added: "A determination will be made by Gayle David Bradshaw, executive vice-president, rules and competition, following an investigation as required by ATP rules."
A decision is likely to be made after the US Open.
In May, Kyrgios was fined after he kicked a bottle, threw down his racquet and hurled a chair before defaulting in the final set of a match at the Italian Open. A month later, he was fined £13,766 for unsportsmanlike behaviour at Queen's.
Back in 2016 he received an eight-week ban for his behaviour at the Shanghai Masters when his efforts were questioned during defeat by Mischa Zverev.
During Tuesday's match at Flushing Meadows, Kyrgios received a code violation for swearing and clashed with umpire James Keothavong for allowing spectators to enter the stadium while he was serving.