Wimbledon doubles champion Michael Llodra fuelled the debate on alleged match-fixing in tennis by saying on Tuesday he had been asked to throw a match four years ago.

"I was in my hotel room and somebody called to ask me not to try too hard the next day," Llodra told French radio. “That was four years ago. I said 'no' and hung up. Now, with what has happened since, I think maybe I was one of the first players to have been approached."  Llodra won this year's Wimbledon title with fellow Frenchman Arnaud Clement, a former top 10 singles player who said on Monday he had been approached to throw a match.

"We have the feeling that a lot of people have been approached, there's a lot of talk about it on the circuit," Llodra said. "Wherever there is money, you have crooks. It's difficult to stop because there is a powerful ring behind it."

The threat of possible match-fixing was being taken very seriously at this week's Paris Masters tournament, the French Tennis Federation (FFT) said.

Betting on matches were being watched for anything suspicious, said FFT general director Jean-Francois Vilotte.  Matches were also being recorded and analysed by former players and ATP supervisors while players were banned from betting at the venue, he added.

The governing bodies of tennis said earlier this month they had full confidence in the integrity of the sport but admitted there was a threat from potential match-fixing. Tennis came under the spotlight in August when a match between Russia's Nikolay Davydenko and lowly-ranked Argentine Martin Vassallo Arguello in Poland was voided by British online betting exchange Betfair because of unusual betting patterns.

Earlier this month, Britain's number one Andy Murray said players believed matches on the ATP Tour were being fixed.