PARIS/BELGRADE (Reuters) - The French financial prosecutor’s office said on Friday it was investigating suspicions of match-fixing in a Champions League soccer match between Paris St Germain and Serbian club Red Star Belgrade.

Earlier on Friday, French sports newspaper L’Equipe wrote on its website that European football’s governing body UEFA had alerted French authorities to possible match-fixing in the Oct. 3 fixture, based on a tip from a “credible” informant.

L’Equipe said the informant had told UEFA before the match that a high-level Red Star official was planning to place nearly five million euros in bets on a five-goal-difference win by PSG, with the complicity of several players. This prompted the investigation.

Paris St Germain beat Red Star 6-1.

The prosecutor’s office said it could neither confirm nor deny L’Equipe’s story.

Both clubs denied any involvement with the allegations made in the newspaper report.

“With the utmost anger and disdain, Red Star vehemently denies allegations that the club’s Champions League match with Paris Saint Germain might have been rigged. Red Star also strongly denies the involvement of any of the club’s officials in any such illegitimate acts,” Red Star said in a statement.

“Allegations from L’Equipe could cause considerable damage to our club’s reputation and Red Star Football Club therefore insists that UEFA as well as the authorities in Serbia and France should fully investigate these suspicions to find out the truth,” Red Star said.

PSG, owned by the state-backed Qatari Sports Investments, also denied any wrongdoing and said it would cooperate with investigators.

“The club categorically rejects any direct or indirect involvement with these suspicions,” PSG said in a statement, adding that it had not been contacted by investigators.

L’Equipe wrote that no evidence of any match-fixing had yet been uncovered by authorities and that all options were possible, from match-fixing to false allegations.

In an emailed response to Reuters, UEFA said it never comments on potential, or the existence of, investigations into alleged match-fixing so as not to compromise the process of such investigations.