The Knights have confirmed to the Daily Telegraph that they are seeking an explanation of the video from Ponga, who is currently sidelined as he recovers from concussion.
The video shows a security guard standing outside of the cubicle before expressing shock as the door opens and Ponga emerges, followed by another person, who the publication reports is allegedly teammate Kurt Mann.
Both were fully clothed.
"Oh! That's a surprise," expressed the guard upon learning the identity of Ponga.
The pair left without argument.
Speaking to The Daily Telegraph, Kalyn's father Andre revealed he had been out drinking to celebrate a house purchase, and he had been sick in the bathroom.
“He made an exciting house purchase Saturday and celebrated with a few mates drinking. Sick in the toilet and his mate went in to help him,” Andre Ponga said.
It's understood the club have been told that Kurt Mann accompanied him to make sure he was okay, and it's understood both players have explained the same story to the club.
Both players are currently sidelined, and could face further scrutiny from the club.
The video has surfaced just hours after Ponga confirmed his season is over, with multiple head knocks leading the Knights to take a cautious approach to his return to play from concussion as he passes through protocols.
Ponga told Triple M Radio on Sunday that he could likely have made his way back for the final round, but medical advice has decided against it given the weeks without contact training following his latest head knock, sustained in Round 19 against the Sydney Roosters.
"I'd be sweet for the last round but doing no contact for the year, it probably would be a wise thing not to play the last round," Ponga said.
"My season's done.
"It's a bit weird. I feel OK now. At the start I felt a bit weird, headaches and whatnot, but I feel alright now.
"It's just hard. I feel OK. I feel fit. I want to play but I guess I'm just going through the protocols at the moment."
The Knights will be out to avoid a bottom-four finish over the final weeks of the season, currently sitting in 14th spot on the ladder, equal with the Canterbury Bulldogs and New Zealand Warriors ahead of them, while four points ahead of the Gold Coast Titans and Wests Tigers behind them.