LONDON -- After spending more than a year under the scrutiny of ATP investigators, Russian tennis star Nikolay Davydenko was cleared by the governing body of men's tennis in a betting probe that brought his reputation and the integrity of the sport into question.
The ATP said it found no evidence of wrongdoing by Davydenko or his opponent, Martin Vassallo Arguello of Argentina, or anyone else associated with their match in Sopot, Poland, on Aug. 2, 2007.
"The ATP has now exhausted all avenues of inquiry open to it and the investigation is now concluded," the ATP said in a statement.
"This is a big relief for Nikolay," Davydenko's agent Ronnie Leitgeb told ESPN on Friday. "It was a nightmare for him."
Leitgeb said he gave Davydenko the news Friday and Davydenko said "all the world can now see I did nothing wrong."
In the 2007 match in question, Davydenko, then ranked No. 5 in the world, withdrew in the third set against the 87th-ranked Vassallo Arguello, citing a foot injury.
According to the London-based gambling Web site Betfair, Davydenko had been a slight underdog to Vassallo Arguello before the match began, despite the significant difference in rankings. He was an even greater underdog, oddly, after he won the first set.
Betfair ultimately voided nearly $7 million in bets after higher-than-normal wagering on the early-round match in the relatively obscure tournament. No money was ever paid but an investigation into the suspicious betting patterns began almost immediately.
"We've got 40 to 50 thousand pairs of eyes on the site at any given time, and everybody was saying, 'There's something wrong here,'" Betfair managing director Mark Davies said of the suspicious betting patterns in a December 2007 interview with ESPN.
"I think it's clear that somebody knew something," Davies added.
That same month, ESPN's Enterprise Unit obtained confidential information about the betting on the Sopot match. The analysis of the betting patterns was conducted by Mark Phillips, a former bookmaker, employed as an investigator with the British Horse Racing Authority
According to Phillips, three Russia-based Betfair accounts risked a total of more than $1.1 million on Vassallo Arguello to win the match, despite the fact that, at the time, he was ranked 80-plus spots lower than Davydenko and never had won an ATP singles title.
Before the match began, according to the Phillips report, the Russian Betfair account operating under the user name "Djults" wagered $540,942 on Vassallo Arguello to win the match. Then, just 15 minutes into the first set, with Davydenko leading 2-1, that same account holder added to the bet on Vassallo Arguello, this time backing him as a 1-7 favorite.
"This suggests the account holder was aware that the match would not be played to completion," Phillips wrote in his report.
London-based professional gambler Mark Bell said he became aware of the suspect betting patterns the day of the Sopot match and became so convinced of a Vassallo Arguello victory that he bet $60,000 on the Argentine, backing him as a 1-10 favorite.
At ESPN's request, in December 2007, Bell reviewed both Betfair's general betting patterns and the confidential information about the Russian accounts contained in the Phillips report.
"I'm certain that from the betting patterns I was privy to, this match was 100 percent fixed," Bell said.
Davydenko was steadfast in his denials of any wrongdoing, in an interview with ESPN in November 2007, and in numerous interviews in the months that followed.
"I don't know how to throw a match. I know that if you are in pain and can't play on, you withdraw," Davydenko said.
Davydenko also denied having any knowledge of the Russian account holders who wagered so heavily against him.
In its statement Friday, the ATP said that it did not receive all of the information investigators were seeking.
For months, Davydenko refused to comply with an ATP request to turn over phone records for himself, his wife, Irina, and his brother, Eduard, who is also his coach.
In November 2007, Davydenko told ESPN he was willing to comply with the ATP request for his personal phone records. In January, while competing at the Australian Open, Davydenko was given a 15-day deadline to turn over phone records for his wife and brother.
While it did not specify who failed to comply with its request for phone records, the ATP's statement of Friday indicated that investigators did not get all they were after.
"Certain individuals declined the ATP requests and appealed them to the independent hearing officer," the ATP said in a prepared statement. "Due to the length of the legal proceedings some of the records were confirmed as having been destroyed by the relevant telephone providers in line with local data protection laws."
Leitgeb said that Davydenko was "very cooperative" with investigators and that he did his "prime right" in hiring a lawyer to handle requests for phone records and other personal information, including from family members. He added that Davydenko adhered to all rulings of an independent hearing officer and "did what was right, under the law."
"There is no doubt that as we move forward with a new tennis-wide Anti Corruption Program we can learn much from some of the challenges faced during this investigation," said Jeff Rees, director of the four tennis governing bodies' newly formed integrity unit, in a statement provided to ESPN.
The ATP said it interviewed "a number of individuals involved in the match" and reviewed betting account details of those who wagered on the match.
Speaking at Wimbledon this year, Davydenko said Russian spectators might have overheard him talking to his wife and entourage in the stands at the Sopot tournament.
"Everything was going on. I spoke in the center court with my wife [in] Russian," he said. "Maybe it's possible, if I can say something, 'I don't want to play or I can retire.' some people can understand."
That sort of inside information could have sparked the flood of telephone or Internet betting, Davydenko explained.
After betting agencies last year presented a list of matches involving irregular wagering during the past five years, and after media reports covered the gambling controversies, tennis authorities conducted an independent probe and identified 45 matches, including eight at Wimbledon, that required further review.
The ATP has approved a list of 15 recommendations from an independent review panel to combat potential for corruption in the sport.
A string of players has been punished for betting violations this year. Last month, France's Mathieu Montcourt was banned from the tour for two months and fined $12,000 after being found guilty of betting on matches.
Doubles specialists Frantisek Cermak and Michal Mertinak were suspended in July, and five Italians also drew similar bans. Other players have said they were approached by people trying to influence a match.
Under new guidelines, players are required to report any suspicious contact from gambling syndicates within 48 hours. Sanctions include life bans for players found guilty of match fixing.
"I welcome the inception of the tennis-wide integrity unit as a positive step towards greater policing of the sport," London-based gambler Bell said Friday when contacted about the conclusions of the ATP report.
John Barr is a reporter and William Weinbaum is a producer in ESPN's Enterprise Unit. Information from the Associated Press was included in this report.