PARIS — French investigators are probing suspicions of match-fixing in Paris Saint-Germain's 6-1 win against Red Star Belgrade in the Champions League group stage on Oct. 3, a source said Friday.

A senior official from the Serbian club is suspected to have bet large sums of money on Red Star losing by a five-goal margin, said the source, who is close to the investigation. The match was played at PSG's Parc des Princes stadium.

French sports newspaper L'Equipe said the Red Star official and accomplices had bet five million euros ($5.8 million) on the match with the aim of winning tens of millions of euros.

The original alert tipoff was received by European football's governing body UEFA which passed on the information to national authorities, another source said.

France's online betting watchdog Arjel said it had seen no evidence of irregular activity regarding the match either in France or in 22 other mainly European countries, or by countries covered by the Global Lottery Monitoring System.

Red Star said they were shellshocked by the claims. "Scandalized and disgusted, Red Star Belgrade rejects suspicions concerning the PSG-Red Star game and the implication of anyone from the club in any untoward dealings," said a statement from the Serbian champions.

PSG said it was "extremely concerned" by the investigation. In a statement, the French club said its contact with Red Star for the match had been completely normal.

"At no moment was any member of the club approached about any issue other than those strictly linked to the organization of the match, for example meetings, visits and the official lunch just as there is for every UEFA Champions League match," PSG said.

"PSG points to its attachment to a fundamental principle of sport, that of the integrity of competition and, consequently, a refusal of any form of practice that could call into question this integrity."

UEFA said it did not comment on ongoing investigations.

Red Star added that they were confident the truth will quickly emerge. "Red Star expects the truth to be established as soon as possible and to be cleared of any suspicion about a club official's connection with these acts," added their statement.

The accusations "are likely to bring great damage to the reputation of our club," added the club who were champions of European in 1991.

"That's why Red Star insists that the competent bodies in Serbia, within UEFA and in France investigate until the end.

"Current technologies, but also other mechanisms have evolved so much that it is virtually impossible for such a case to remain unclear."

Approached by AFP, the Serbian Football Federation had not yet reacted to the allegations on Friday night.

In the game concerned, Brazilian star Neymar scored a hat-trick with PSG's other goals coming from Edinson Cavani, Angel Di Maria and Kylian Mbappe. Marko Marin scored Red Star's only goal.

The allegations come at the end of a week in which the Belgian league was rocked by a corruption scandal.

Belgian prosecutors on Friday charged 19 suspects and detained nine in a massive fraud and match-fixing inquest that has mired Belgium's elite league in scandal.

The charges came after police on Wednesday carried out a massive operation in Belgium, arresting 29 people, 10 of which were released without charges.

Among the detained were at least three players' agents, a referee, and a top executive from a major football club, a statement from prosecutors said.

Meanwhile, shipping magnate Vangelis Marinakis, the owner of Olympiakos, was told Friday that he will face trial accused of corruption in Greek football, the Athens Court of Appeals decided.

Marinakis, former Greek football federation president Giorgos Sarris, and an ex-legal advisor have been accused of forming a criminal organization and manipulating results of matches. In all, 28 people are facing charges in the Greek case. — AFP