MELBOURNE, Australia  Nikolay Davydenko has won 14 straight matches against some of the best players in the world, including two against Roger Federer, whom he will meet Wednesday in the Australian Open quarterfinals. In the past week, Davydenko has come out of what had been an inscrutable shell as well, proclaiming that his rivals are scared of him and that he would rather have his millions in prize money than fame.  “I’m not Paris Hilton,” he said.  In fact, money comes up a lot in his conversation, a tendency for which he blames his heritage. “Russians always talk about money,” he said.  Davydenko’s turn in the spotlight here, however, has returned attention to tennis’s uneasy relationship with gambling. After all, Davydenko was at the center of a match-fixing investigation involving a 2007 match. That touched off a wider scandal in tennis in which at least a dozen ranked players said they had been asked to throw matches or had heard of similar approaches to others.  Tennis’s major governing bodies commissioned a report, which recommended that 45 matches played in the previous five years be investigated further because betting patterns gave a “strong indication” that gamblers were profiting from inside information. Subsequently, the report’s author, Jeff Rees, a London police officer who has worked on anticorruption programs in other sports, was named to create a Tennis Integrity Unit.  Stickier still is the fact that Betfair, the British gambling company that refused to pay $7 million of bets on Davydenko and brought the scandal to light, is a sponsor of the Australian Open. In fact, Betfair Australia pays Tennis Australia a share of revenue from wagers on matches during the tournament.  “We’re not opposed to gambling,” said Steve Ayles, a spokesman for the Australian Open. “It is part of our Australian culture and it is widely accepted.”  Betting is indeed part of the sporting culture here. Betting parlors are dotted throughout the city and take bets on cricket, rugby and N.F.L. football as well as tennis. Furthermore, other betting companies sponsor the WTA Tour’s Hobart International in Australia and the men’s Valencia Open in Spain.  Officials for the ATP and WTA Tours say they have no control over individual tournaments and how they sell sponsorships.  Some players say they believe the concern over gambling is much ado about nothing.  “I say you can have a sponsor that wants to advertise, that I don’t really see how it affects our roles,” Andy Roddick said. “I think we all know what we can and can’t do. At this point with this economy, I do think it would be foolish to say no to willing sponsors. You know, it’s still up to us as players to act responsibly.”  Neither Rees nor anyone else from the Tennis Integrity Unit would talk on the record about what it was doing to prevent gamblers from having access to players for a possible match fix. The unit has been busy, though.  At a warm-up tournament in Brisbane, Australian bookmakers reported a suspicious amount of money coming in on Harel Levy of Israel, ranked 118th, to defeat No. 70 Michael Llodra of France in straight sets. Levy did win, 6-2, 6-3, at odds of $5.50. While no one has suggested that Llodra threw the match, there is concern that information about an injury might have leaked out.  In fact, the Integrity Unit is focused on weeding out hangers-on from the tours.  Ekaterina Bychkova of Russia, who is ranked 120th, was forced to skip the Australian Open after being suspended for 30 days and fined for being found guilty of failing to report an offer made to her to influence the outcome of a match.  It caused a minor row with some players who thought she had been punished too harshly. Svetlana Kuznetsova, ranked No. 3, complained that players had not been properly informed that they were required to report approaches.  But Kim Clijsters, the United States Open champion, said she and most players knew the rule, were trying to honor it and believed it was necessary to keep tennis on the up and up.  “It’s something that I think I take very seriously,” she said. “If people approach me, it will be the first thing I do: try to talk to someone from the tour or even some of my own people in my group, and it’s maybe up to them to go mention it to the tour.”  The ATP cleared Davydenko of fixing a 2007 match in Poland in which he retired because of an injury with Martín Vassallo Arguello ahead, 2-6, 6-3, 2-1. Davydenko’s manager, Ronnie Leitgeb, has said that ATP investigators told Davydenko’s camp that nine Betfair accounts traced to Russia stood to make $1.5 million if he lost and that two other unknown account holders were to make nearly $6 million.  But the ATP acknowledged that its investigators were unable to review the phone records of Davydenko’s wife and brother, which were first withheld and then destroyed.  Davydenko has maintained he did nothing wrong and has speculated that Russian spectators at the tournament might have overheard him talking to his wife and his entourage in their native language and thus known he was having trouble in the match.  This era of insider trading of information about injuries and other things is why Clijsters says her peers need to be vigilant about keeping their own counsel and following the rules.  “What is the pity about the sport, that a lot of money is being able to be made outside of what’s happening on the court,” she said. “Sometimes that has a little bit of a negative influence. But luckily enough, I think it doesn’t happen that often.”
A 2007 match involving Nikolay Davydenko kicked off an investigation of possible entreaties to fix matches, and a larger discussion about the role of gambling in tennis.