"It happened to me but I will not tell you where or how," Clement told reporters after his first-round defeat by Russia's Mikhail Youzhny at the Paris Masters Series tournament.
"I didn't hesitate for a second, I said no," added the 29-year-old, who was runner-up at the 2001 Australian Open and is now ranked 53rd in the world.
"It may be different for a guy who's not that high up in the rankings and who has financial problems.
"It's very serious. I can't imagine that a top 10 player could accept that but it's hard to imagine as well that guys go to tournaments to make such offers. I haven't heard many players say it happened to them."
The threat of possible match-fixing is being taken very seriously at the Paris tournament, French Tennis Federation (FFT) president Christian Bimes said earlier on Monday.
"We consider this a serious problem," Bimes told a news conference.
'DREADFUL DISEASE'
"It is a dreadful disease which is a threat for tennis worldwide," Bimes added. "We have to act straight away and be as severe with this as we are with doping."
Betting on matches at the Paris event was 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.
"We have contacted police," Vilotte said. "If we were to trace a suspicious amount of money placed on one match and to notice anything irregular during that match, we would hand over the information to police and they would launch an official investigation."
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.
Davydenko, who has strenuously denied any wrongdoing, was fined $2,000 for not trying hard enough during his shock defeat by Croatian qualifier Marin Cilic at the St Petersburg Open last week.
Earlier this month Britain's number one Andy Murray said players believed matches on the ATP Tour were being fixed.
