MELBOURNE • Match-fixing is commonplace in tennis' lower levels and efforts to fight it are inadequate, a senior anti-corruption official said after cheating claims rocked the sport during the Australian Open.

After an explosive report claimed match-fixing was repeatedly going unpunished, Chris Eaton, director of integrity at the International Centre for Sport Security, criticised tennis' "opaque and secretive" anti-corruption body.

He said professional betting analysis showed "nil manipulation" of matches at tennis' top levels, where players are highly paid and less susceptible to bribery.

"However in the second and lower levels, manipulation indicators are heavy and regularly occurring," the former Fifa security chief said via e-mail. "We are not the only sport integrity organisation to observe this."

Eaton's comments follow the BBC and BuzzFeed report that said 16 players who had reached the top 50 over the past decade had repeatedly been suspected of fixing matches, but were never punished.

The tennis authorities rejected any suggestion that evidence was suppressed and defended the workings of the Tennis Integrity Unit, which was set up in 2008 and has landed 18 convictions, including six life bans.

Eaton also noted tennis was the third most popular sport, behind football and cricket, for betting worldwide "and as a direct consequence it is third in the magnitude of identified suspicious matches".

"Tennis is not as lucrative for fixing as football or cricket. But it takes less effort to fix individual outcomes in a tennis match, so the frequency of winning on a single match can be vastly higher than in cricket and football," he said.

AGENCE FRANCE-PRESSE