The governing body of men's tennis will use the British Horseracing Authority's (BHA) corruption expertise when it investigates a match involving Nikolay Davydenko of Russia.
The ATP was alerted to the possibility of a betting scam by online bookmaker Betfair, which voided bets on Davydenko's Aug. 2 second-round match against Martin Vassallo Arguello at the Poland Open.
The fourth-ranked Davydenko had won the first set 6-2, but then lost the second 6-3 to the Argentine and was trailing 2-1 in the third when he withdrew because of a foot injury.
Betfair reported an usually high number of bets on the match -- mostly on 87th-ranked Arguello to win, even after the first set.
"Betting patterns before the market were as expected for this match," a Betfair spokesman said on Friday, explaining the turn of events that raised their suspicions.
"But before a ball was struck Arguello the world number 87 had become slight favorite. Davydenko's odds continued to drift and after he won the first set 6-2 he drifted even further. At that point it was clear something was not right."
Betfair said that US$7.3 million of bets had been placed and accepted on the match.
"Normally for a match like that it would have been around US$1 million dollars," the spokesman said.
The ATP approached the BHA, which has vast experience in dealing with betting scams, and the tennis body said it would also make use of its sophisticated account analysis systems.
Davydenko's agent, Eckhard Oehms, said two days after the match that the Russian was innocent of any suspicions.
"We've go nothing whatsoever to do with that," Oehms said. "Neither Nikolay nor his coach nor me nor anybody out of our entourage has been involved in this. This is a matter that is important to us. We can't have his reputation being tarnished by things like this."