KEY POINTS:
Bookmakers are concerned it may be widespread, John McEnroe is worried some players see it as "a cheap way to make a buck", and Andy Murray claims that "everyone knows it goes on".
The problem for tennis, however, is that for all the recent allegations about match-fixing and
illegal betting, nobody has provided the sport's authorities with evidence that the talk is anything more than hot air.
The Association of Tennis Professionals, concerned at a growing number of unsubstantiated headlines about corruption, has thrown the tennis ball firmly into the court of the accusers, some of whom have been willing to talk publicly but unwilling to provide any concrete evidence.
Players on the men's tour will now face disciplinary action if they fail to tell the authorities within 48 hours if they are approached to throw matches. If presented with any such allegations, the ATP says it will look into them with all the vigour it has shown in its continuing investigation into a match in Poland two months ago.
Betfair, the online betting exchange, voided all bets on a match at Sopot between Nikolay Davydenko, the world No 4, and Martin Vassallo Arguello, the No 87, after suspiciously heavy betting on the lower-ranked player, even when he was losing.
Davydenko eventually retired with a foot injury. Both players deny any wrongdoing, but the ATP is still investigating and has employed two former Scotland Yard detectives to look into the case.
There have been a number of subsequent allegations of corruption, but the Sopot match remains the only case where a betting company has deemed it appropriate to cancel all bets.
Gilles Elseneer has claimed he was offered €100,000 to lose at Wimbledon two years ago, his fellow Belgian Dick Norman said he had been asked to provide in-depth information on other players' fitness and the former British Davis Cup player, Arvind Parmar, said he was offered money to lose a match at a Challenger event.
The International Tennis Federation, which is responsible for the Grand Slam tournaments, investigated a match at Wimbledon last year after Betfair reported substantial betting on Richard Bloomfield to beat Argentina's Carlos Berlocq, ranked 170 places higher than the Briton. Bloomfield won, but the ITF investigation found no evidence of corruption.
"We require detailed information to enable us to mount an effective investigation," an ATP spokesman said .
"If players have been approached about fixing matches but haven't informed us about it then they are letting the sport down."
The ATP was the first organisation after the Jockey Club to sign a memorandum of understanding with Betfair, under which the company passes on information both about suspicious betting and about individuals breaking tennis rules by gambling.
The ATP, which has similar agreements with 13 other companies, has had an anti-corruption programme in place since 2003, forbidding players and members of their entourage from gambling. A recent article in L'Equipe, the French sports daily newspaper, quoted one player who estimated that up to 80 per cent of coaches regularly use online betting websites.
The ATP will meet the sport's three other main ruling bodies - the Grand Slam tournaments, ITF and Women's Tennis Association - with a view to establishing a joint "integrity unit" to combat corruption.
"We want to bring in experts in this area to review the sport and give us an idea of what is required to police it properly," the ATP spokesman said. "The different bodies have been united in their desire to fight corruption, but until now we've tended to go about it in different ways."
The ATP has asked Andy Murray's agent to arrange a meeting with the British No 1 to discuss his claims that it was easy to throw a match.
"It's difficult to prove if someone has 'tanked' a match or not tried because they can try their best until the last couple of games of each set and then make some mistakes, a couple of double-faults, and that's it," Murray told the BBC. "Everyone knows it goes on."
- INDEPENDENT