Adam Elliott is under investigation by the NRL integrity unit after a video featuring the Bulldogs star began circulating on Thursday.
Canterbury released a statement on Thursday evening confirming the club was aware of the situation.
"The Canterbury Bankstown Bulldogs would like to confirm that they are aware of a video having surfaced involving Adam Elliott," the club statement claimed.
"The video relates to something that was filmed at a private gathering five years ago. The club has informed the NRL Integrity Unit of the matter."
The old video shows Elliott dancing with two drinks in his hands in front of a camera at a private gathering attended by former teammates.
He is seen to be partially naked in the video.
There is no suggestion of any illegal behaviour by Elliott.
Channel 7 senior rugby league journalist Michelle Bishop reported Thursday the Bulldogs claim Elliott is the victim of a "dirty tricks" campaign against the club.
The report claims the video of Elliott was shopped around to several media companies in Australia.
The Bulldogs reportedly fear the release of the video may have been an attempt to harm Elliott's reputation and his market value in the middle of his ongoing contract negotiations.
It comes just days after it was revealed Elliott has hit a stalemate with the Bulldogs in his ongoing contract negotiations.
The Daily Telegraph reported the club is on track to miss out on Elliott's signature after "low-balling" him with the club's first reported contract extension offer.
Elliott has been a standout player for the Bulldogs in 2020, but he is now reportedly considering preliminary interest from the Dragons and Raiders as he continues to weigh up his future.
Elliott said last month that his first priority was to remain with the club.
"I'd jump in front of a train for the club but I've got a young family now and it's that point in my career where I have to make smart decisions, informed decisions. I'm just going to turn up and try and play as good as I can for the Bulldogs and, hopefully, that will sort itself out," Elliott told Fox League.
Elliott was famously fined $25,000 by the Bulldogs in 2018 after he was spotted dancing nude around teammates during the club's Mad Monday end of season function at the Harbour View Hotel in The Rocks, Sydney.
He was in 2019 given a good behaviour bond after he pleaded guilty to wilful and obscene exposure following a police investigation into the function.
He was handed a two-year good behaviour bond, but he was not fined and no conviction was recorded.