Exclusive: Wimbledon on high alert over suspected match-fixing rings

Up to 12 players feature on official 'watch list' following betting irregularities

The Lawn Tennis Association wants to boost its chances of success in the build up to London 2012 (GETTY IMAGES)

Between six and 12 players due to compete in the men's singles at Wimbledon are on a "watch list" of individuals under scrutiny by the game's authorities because of past involvement in matches where suspicious betting happened and match-fixing was suspected. The revelation comes from an investigation by The Independent into corruption in tennis, and into the methods that the authorities, including the world men's governing body, the ATP, are using to stamp it out.

The Independent understands the full "watch list" includes Russians, Argentines, Italians, Spaniards and players of other nationalities, including men from inside the top 50 as well as those at the lower reaches of the game.

A senior source said: "We have interests in the activities of certain players and there are players whose matches we follow closely. It would be ludicrous to think, with so much money involved in betting, that there is no malpractice. A few of [the players being watched] aren't the ones you'd necessarily suspect while others who've had unjustified rumours trotted out about them are not of concern."

The investigation has discovered that the ATP knows the identities of a group of big-time gamblers, in Russia in particular and also in Italy, who have wagered on "suspicious" games. Details of the only time a match-fixing allegation has been aired in court have also surfaced and are revealed today, along with information on how the ATP failed to provide records that might have helped the prosecution.

The top-level source said one challenge in fighting corruption is "sifting self-perpetuating gossip from hard evidence of corruption". Another is stopping the use of "inside information" where "a privileged few profit for financial gain".

Then there is the challenge of catching "the small minority" whom the authorities believe are actively corrupt. The source said: "It's stupid to say there aren't some players tempted by what they're being offered to fix matches."

Ahead of Wimbledon, which begins on Monday, these revelations add weight to the growing fears within the sport and the gambling industry that major tennis tournaments are being targeted – successfully in some cases – by match-fixers. A wide range of gambling industry sources say there have been "ongoing concerns" about tennis.

An investigation is underway into Monday's first-round match between Spain's Oscar Hernandez and Austria's Daniel Koellerer at the Ordina Open in the Netherlands, after "unusual" bets on Hernandez, who won. The Independent can reveal a 29-year-old male Russian spectator was arrested yesterday at that tournament for gambling on a laptop courtside, which is forbidden.

The Independent has also learnt that a match in Kitzbühel, Austria, last month, was flagged up to the ATP as "of concern". There was also irregular betting on at least one match at the Monte Carlo Masters in April. France's Jean-René Lisnard's first-round win, 6-2, 6-2, over Belgium's Christophe Rochus led to non-payment of bets by some bookies.

That match was referred to the Gambling Commission (the industry watchdog), as well as to the Tennis Integrity Unit (TIU), tennis's in-house crime-stopping team.

The head of the TIU is Jeff Rees, a respected detective who served in the Metropolitan Police for 32 years and who earned his reputation as a leading sports integrity expert working in cricket's anti-corruption unit. It was Rees and his fellow integrity expert, Ben Gunn, who authored tennis's Environmental Review of Integrity in Professional Tennis, published in May last year, which recommended the formation of the TIU.

The Independent put its findings to the man at the top of men's tennis, Adam Helfant, the ATP's executive chairman and president. In response, the ATP released a statement: "Since January 2008 the ATP, Grand Slams, ITF and Sony Ericsson WTA Tour have had a Tennis Integrity Unit led by Jeff Rees. All related matters are dealt with by his unit and we don't intend to comment on any allegations or media stories."

The Independent put a series of questions to Rees about tennis integrity and TIU's work to which he declined to comment.

Those questions included asking what has happened to investigations into 45 matches that Rees's Review said, almost 14 months ago, had caused "specific concerns from a betting perspective". The Independent has been told by an impeccable source: "The findings might never be made public."

The May 2008 Review said tennis's authorities knew about suspicious betting activity by 27 Betfair account holders in two countries. The Independent can reveal today those countries were Russia and Italy, and that three Russia-based account holders in particular placed enormous sums on the infamous match between Russia's Nikolay Davydenko and Argentina's Martin Vassallo Arguello in Sopot, Poland, in August 2007.

Betfair alone took more than $7m in bets (£3.4m) on that match, or 10 times normal levels. Davydenko was No 5 in the world and should have been hot favourite against Arguello, then No 87.

But Davydenko was the underdog on Betfair, and despite that, one Russian Betfair customer, "Djults", wagered $540,942 on Arguello before the match, and then more when Davydenko was one set ahead.

A second customer, "Sgenia", bet $368,036 on Arguello to win, even when he was a set down. The gamblers were behaving as if certain that Arguello, even while losing, would win.

A third customer, "Ruster", had held a Betfair account since 2005 and had averaged $800 per bet until that match. Then he bet $253,833 at odds as short as 1-11 on Arguello. Davydenko subsequently retired, injured, in the third set, making Arguello the winner. Betfair took the unprecedented step of voiding the market.

Both players have always denied any wrongdoing. Contrary to popular belief, nobody was ever charged with any misdemeanour. An ATP investigation, which failed to gain access to some phone records, concluded last September with a carefully worded statement that said: "The ATP has now exhausted all avenues of enquiry open to it."