According to French publication L’Equipe, authorities in France are probing the outcome of the match at the Parc des Princes after receiving information from UEFA.
It is claimed that, in the days leading up to the match, UEFA was informed that a senior figure at the Serbian club was planning on placing nearly €5 million (£4.4 million) on his own team to lose by five goals.
The Champions League Group C fixture ended in a 6-1 victory for the Ligue 1 club, with Neymar scoring a hat-trick and Kylian Mbappe, Edinson Cavani and Angel Di Maria also on the scoresheet.
Marko Marin had reduced the deficit with 16 minutes remaining, giving a scoreline of 5-1, before Neymar scored his third, and PSG’s sixth, in the 81st minute.
France’s financial prosecutor’s office confirmed an investigation has been opened, but declined to comment further.
Both clubs have reacted to the claims with a mixture of shock and indignation. A statement from the Serbian club read: “FC Red Star, with the highest anger and abomination, rejects the story L’Equipe published today about a suspicious result in the PSG vs Red Star match and involvement of anyone from our club in possible wrongdoing.
“The article could seriously damage our club’s reputation and that is why we insist that UEFA and investigators in Serbia and in France investigate the whole story and get the truth.”
“Today’s technologies and other mechanisms are so improved that it is basically impossible to leave this case unsolved. FC Red Star expects to get the truth at short notice and remove any doubt about our involvement.”
Honorary Red Star president Dragan Dzajic told L’Equipe: “This is the first I have heard of it. I know absolutely nothing about this. It is not possible. It is untrue.”
A statement from PSG read: “It is with utmost amazement and indignation that we have learned of the information that you have shared.
“At no time has a member of the club been asked to discuss any matters other than those strictly related to the organisation of the match, namely meetings, visits and other standard lunchtime protocol in the build-up to Champions League matches.”
ARJEL, the body tasked with regulating online gambling in France, told the newspaper it had not noticed any suspicious betting patterns on the game.
The probe has been launched just days after raids on some of Belgium’s leading football clubs resulted in nine people being arrested, including a prominent referee and three agents.
A total of 19 people are facing charges ranging from match-fixing to money laundering in the country’s biggest footballing scandal in decades.