World champion Ronnie O'Sullivan said on Tuesday that Stephen Lee is not the only player guilty of fixing snooker matches.

"I've heard there're many more players who throw snooker matches. I suppose Steve Lee was just caught out," O'Sullivan tweeted.

Lee, 38, is awaiting sentence after a tribunal decided he had fixed seven games in 2008 and 2009, the BBC reported.

World Snooker chairman Barry Hearn said O'Sullivan could be charged if he refuses to name players.

"No need to worry if you got nothing to hide. But plenty of people have got loads to hide. That's why there is no free speech. They're hiding," O'Sullivan added in a further tweet.

"They will prob (sic) fine me for talking about it. They don't like you doing that. Like to keep things under the carpet."

Hearn said, "If he has names and he knows of incidences, he has an obligation and a duty to report them and failure to do so will put him in breach of his player's contract."

"World Snooker will be writing to Ronnie to say that under his player's contract, it is his responsibility to report any incidences he's aware of and failure to do so would lay him open to a charge of bringing the game into disrepute."

Lee had denied the allegations of match fixing but a tribunal in Bristol concluded that Lee deliberately lost games against Ken Doherty and Marco Fu at the 2008 Malta Cup.

They also found him guilty of agreeing to lose the first frame against both Stephen Hendry and Mark King at the 2008 UK Championship and throw matches by a pre-determined score to Neil Robertson at the 2008 Malta Cup and to Mark Selby at the 2009 China Open.

He similarly conspired to lose his 2009 World Championship first round match to Ryan Day, going on to be defeated 10-4.