French authorities are currently investigating whether external factors influenced the outcome of the game.

Paris Saint Germain and Red Star Belgrade are reportedly alarmed by claims which suggest that the outcome of their Champions League group-stage on October 3 was fixed. Reports suggest that French investigators have started probing the matter after the European football governing body UEFA passed on the information following a tip-off.

The said Group C encounter which took place at the Parc des Princes saw Neymar Jr hitting a hat-trick while Angel Di Maria, Edinson Cavani, and Kylian Mbappe got the remainder of the goals. Ex-Chelsea player Marko Marin grabbed the consolation goal for the visitors.

A report by French news outlet L'Equipe indicates that a senior official from the Serbian club is suspected to have placed a bet worth a large sum of money on Red Star to lose by a five-goal margin. The amount used in betting by the senior official in collaboration with other accomplices is €5million with the returns worth tens of millions of euros.

In the development of the issue, Paris Saint-Germain issued a statement on Friday to address their concerns. The club stated: "The Club [Paris Saint-Germain] categorically rejects any and all direct and indirect implication in relation to these suspicions and would like to point out at no moment has Paris Saint-Germain been approached by the National Financial Court in charge of the investigation.

"Paris Saint-Germain remains at the disposal of the investigators and will not tolerate the slightest attack on its reputation nor that of its officials. To that end, the Club reserves the right to take legal action against any party that makes defamatory statements against the club and/or its officials.

"The Club reaffirms its profound attachment to the fundamental principle of sport, which is and always will be the integrity of its competitions. Red Star Belgrade also stipulated that it was staggered by the claims.

"Scandalised 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 club.