Andy Murray, the British No 1, believes players on the tennis circuit are involved in match-fixing.

The 20-year-old fears the temptation to cheat is too great for players who struggle to make a living in the professional game.

"It doesn't really surprise me," Murray said. "Some guys have to come to tournaments like this every single week and the first-round loser's cheque is sort of €2,500 and they have got to pay for their air fares and, you know, it's only a ten or 12-year career so you have to make all your money while you're still playing."

Murray feels the nature of the sport makes it difficult to prove when someone is trying to engineer an outcome. "It's not really acceptable, 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," he said.

"It's pretty disappointing for all the players but everyone knows it goes on."

The ATP have a zero tolerance policy towards players who become involved in gambling. They are investigating betting patterns concerning a match in Poland between Nikolay Davydenko, of Russia, and Martin Vassallo Arguello, of Argentina.

The Russian's price drifted out despite him winning the first set and he later pulled out of the match due to injury. Davydenko denies any wrongdoing.