Red Star travel to Anfield for their next Champions League group game before heading home to Belgrade for the return fixture in November. The Brazilian scored twice in as many minutes in the first half, while Edinson Cavani and Angel Di Maria gave the hosts a 4-0 lead at half-time.
According to French publication L'Equipe, French prosecutors have begun looking into the match-fixing allegations after a tip-off by UEFA.
However, a report from L'Equipe details allegations UEFA received of match-fixing by Red Star in which a senior member of the Serbian club, with others, meant to place a bet of several million euros on the team to lose by five goals.
Red Star have now released a statement vehemently denying the accusations, and demanding an UEFA investigation into the matter in order to clear the club's name.
PSG and Red Star are in Group C, along with Liverpool and Napoli, but there is now a cloud of suspicion hanging over the game played between the pair, a game which PSG won 6-1.
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"Red Star with highest anger and abomination rejects the story L'Equipe published today about a suspicious result of the PSG-Red Star match and the involvement of anyone from our club in possible wrongdoing", the Serbian club's statement read.
"This is not possible, this is not true", Red Star Belgrade President Dragan Dzajic L'Equipe reported.
Red Star deputy spokesman Nebojsa Todorovic told Agence France Presse that he "cannot in any way comment on this", while Milan Vukovic, the spokesman for Serbia's football association, was unavailable for comment.
UEFA said it did not comment on ongoing investigations. I know absolutely nothing about this. It is not possible.
"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", they said in a statement.