Italian media reported that Turin magistrates had sought information about 14 personal cheques for a value of more than 1.5 million euros signed by the Italy captain in 2010 and placed at a betting agency in a Parma tobacconist's shop.
The reports, carried on the websites of several newspapers, said the investigators had sought information from magistrates investigating the widening match-fixing scandal in Italian football to see if they were linked to illegal betting.
Marco Valerio Corini, the lawyer for the 34 year-old Juventus goalkeeper, denied any suggestion of wrongdoing by his client, who is not under investigation by police.
"There is nothing which could even carry the faintest suggestion of a connection between Gianluigi Buffon and any betting activity that would concern him in any irregularity either with respect to federation rules or criminal law," he told SkyTG24 television.
"There is not the slightest foundation for any suggestion that this is connected with a bet."
The latest upset to hit Italy comes days after police visited the team's training camp at Coverciano and placed defender Domenico Criscito under investigation on suspicion of involvement in match-fixing.
Criscito was subsequently dropped from Cesare Prandelli's squad so that he could have time to clear his name.
Since last year, Italian football has been tangled in a widening match-fixing scandal during which a string of past and current players have been arrested and the coach of Serie A champions Juventus placed under investigation.
Buffon, a key player in Juventus' triumphant Serie A season and a member of Italy's 2006 World Cup winning team, has been sharply critical of the way in which information regarding the match-fixing investigation has been leaked to the media.
Gambling on sporting events is legal in Italy although Italian Football Federation rules restrict betting on football matches by players.