Russian Nikolay Davydenko has launched a stinging attack on British number one Andy Murray over the Scot's comments on betting in tennis.
Murray said in an interview that it was common knowledge that matches were thrown, comments he has subsequently distanced himself from.
The ATP is conducting an inquiry into a match between Davydenko and Argentine Martin Vassallo Arguello at the Sopot Open in Poland in August, after Internet bookmaker Betfair voided all bets on the match because of what it said were irregular betting patterns.
The Russian won the first set of the match before retiring with a foot injury.
Davydenko said: "I don't know why he (Murray) is talking about this. A guy talking about this is trying to be more famous than he is on the tour, because if he tells something then he knows.
"We need questions from the ATP why he knows this or what he does know.
"That is why from him it is stupid to say something like that, this is something that normally nobody knows.
"I don't know how Murray's got this information. For me it's surprising.
"How does he know everything about gambling? He just says 'I know', ask him how he knows. For me that's the interesting thing - why he knows and from who he knows,"
World number four Davydenko also announced that he has pulled out of the Madrid Masters because of an elbow injury.