UEFA have denied claims that Euro 2008 qualifiers are part of a match-fixing investigation but have revealed doubts about one Intertoto Cup match were so serious it was referred to their disciplinary committee.

European football's governing body confirmed they are continuing investigations, in conjunction with Europol, into 15 matches played this season which may have been fixed.

A report by German magazine Der Spiegel said UEFA are concerned by up to 26 matches, dating back to July 2005.

Der Spiegel claimed among the matches under suspicion are three fixtures from the third preliminary round of the Champions League, two in the UEFA Cup and one in the qualifiers for Euro 2008.

The magazine also reported the matches mostly concerned teams from eastern and southern Europe, notably Bulgaria, Serbia and Croatia but also the Baltic states in the north.

However, UEFA have insisted there is no suspicion hanging over any of the results from qualifying for Euro 2008, as they prepare for Sunday's draw for next summer's finals.

"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," said a statement from European football's governing body.

"In this respect we were informed of some unusual betting patterns in the preliminary rounds of UEFA club competitions.

"In one case, a second round UEFA Intertoto Cup match, the disciplinary inspector considered the circumstances serious enough to bring the case before the UEFA Control and Disciplinary Body.

"At its meeting on Thursday, November 29 it requested further investigations be carried out before taking a final decision.

"For the avoidance of doubt, there are no investigations under way into any of the qualifying matches for 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.

"While any investigation is ongoing it is not appropriate for UEFA to issue further comment."

Former Football Association compliance officer Graham Bean believes the suspected fixing of 15 European games this season could "potentially [be] one of the most serious things that has ever happened in world football".

Bean said: "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, perhaps as a result of betting patterns, or individuals telling them what they know."

The topic was raised at a two-day conference in Brussels earlier this week convened principally to tackle hooligan violence in sport.

UEFA president Michel Platini and European Commission vice-president Franco Frattini have agreed to hold a conference next year to look at "criminal phenomena" in sport, such as money-laundering, match-fixing and illegal betting.

UEFA are not putting any time-frame on when the investigation might be complete.

According to Der Spiegel, five UEFA officials flew to Europol headquarters in The Hague in early November and handed in a 96-page dossier detailing each case and what methods were used to fix the games.

The UEFA report was said to have details of millions of euros being pocketed by Asian betting syndicates based on the results of the relevant games.