NSW Police are investigating claims of match fixing in a third NRL game.
Officers from the state's Organised Crime Squad are making inquiries after the Seven Network reported an $18,000 bet was placed on Manly's round seven loss to Parramatta earlier this season.
"The Organised Crime Squad is in the early stages of examining information relating to allegations of match fixing in the NRL," a NSW Police spokeswoman told AAP.
The match is the second between the two sides believed to have been investigated for fixing.
The NRL confirmed in June they were reviewing Manly's losses to the Eels and South Sydney last season.
The Sea Eagles lost both fixtures. They were outsiders for the clash with the Rabbitohs but short-priced favourites to beat the Eels.
Controversial high-stakes punter Eddie Hayson has been linked to the match-fixing allegations but denies any involvement.
The Sea Eagles have also lashed out at the allegations, the club saying in June it's 70-year reputation for fair play had been "unfairly tarnished" by the claims.
Former Sea Eagles coach Geoff Toovey told NRL360 in June he had questions after his team's poor performance against the Eels in round 24 last year.
"Could we be that bad? I don't think so. Maybe we could be, but possibly there was some underlying issue there," Toovey said.
"But I would find that incredibly hard to believe that players would sink that low."
Both clubs meet again on Friday night at Pirtek Stadium.
The NRL said on Friday it was continuing to cooperate with authorities in regards to the allegations.
"Our position has not changed ... we will take whatever action is necessary to protect our game," an NRL spokesman said.
"Anyone convicted of match fixing can expect to be banned for life but, at this stage, no one has been charged and we should avoid jumping to conclusions."
The round-seven clash at Brookvale Oval was locked at 8-8 at halftime but the Eels scored three tries in the final 12 minutes to claim a 22-10 victory.