Uefa has given police a list of 15 matches it suspects may have been fixed, a senior Uefa source has said.
News of the match-fixing investigation came while Uefa officials and coaches gathered in Lucerne ahead of today's draw for Euro 2008, to be played in Switzerland and Austria.
According to the source 15 matches are under investigation and being dealt with by Uefa's disciplinary committee".
The matches under suspicion were played in a variety of Uefa competitions including Champions League qualifiers, Uefa Cup qualifiers and Uefa Cup and Intertoto Cup ties.
Uefa would not confirm when the matches took place although the source said a 96-page dossier handed to Interpol last month went back to July 2005.
Irregular betting patterns on the matches alerted Uefa to the possibility that some might have been fixed.
"Uefa introduced, over one year ago, an early warning system in order to monitor irregular betting activities, and agreed to work together with the appropriate police authorities," Uefa said in a statement on its website (www.uefa.com).
"In this respect we were informed of some unusual betting patterns in the preliminary rounds of Uefa club competitions. "For the avoidance of doubt, there are no investigations underway into any of the qualifying matches for Uefa Euro 2008.
"As a responsible governing body, Uefa is continuously monitoring football betting patterns and will take disciplinary action in any cases where that may be justified."
Graham Bean, an ex-police officer and former head of the English FA's Compliance Unit, said the affair could become the biggest of its kind to hit the international game.
Mr Bean told the BBC World Service yesterday: "These are clearly exceptionally serious allegations but having said that they will be extremely difficult to investigate.
"Clearly for Uefa to pass this report across (to the police) they must have evidence of some kind... "...This is potentially one of the most serious things that has ever happened in world football."
Earlier this week, Uefa opened an investigation into the Intertoto Cup match between Bulgarians Cherno More and Macedonia's Makedonija on July 7th, which Cherno More won 4-0.
The Bulgarian club have strongly denied any wrongdoing. "It's an extremely unpleasant case but we think that the charges are unwarranted," Cherno More's lawyer Mihail Statev said at a news conference on Tuesday.