MADRID, Spain -- The ATP is looking into reports of possible match-rigging, but the head of the men's tennis tour doesn't believe any players are involved.

"I suppose anything is possible in some respects, but I believe that our guys, the athletes in tennis, are among the cleanest in any sport anywhere," ATP chief executive Mark Miles said.

Miles, who spoke Monday during the Masters tournament in Madrid, was responding to a report in a British newspaper alleging possible match-rigging in men's tennis.

The ATP got permission from the online gambling company Betfair to see its clients' records, part of an effort to make sure players aren't involved in fixing matches.

"We're doing everything we can do to collect all the information possible about what goes on out there in a big, decentralized cyber world," Miles said.

Last week, bookmakers reportedly suspended betting six hours before a match in Lyon, France, between Yevgeny Kafelnikov and Fernando Vicente after a big wager was placed on Vicente, winless since June.

Vicente won in straight sets. There was no suggestion that either player was involved in any wrongdoing.