Rugby league must endure another alcohol-fuelled drama with Queensland's State of Origin preparations blown off course by an assault investigation.

Rookie winger Will Chambers is at the centre of allegations he pushed a patron and sparked a scuffle at a Brisbane bar in the early hours of Wednesday morning.

Chambers, only named to make his Origin debut 15 hours before, had been with several teammates at the Down Under Bar at a late-night bonding session.

Police and the Queensland Rugby League have confirmed they are investigating the incident.

Tristan Furniss, 24, has made a formal complaint against Chambers and was questioned at length on Wednesday.

Furniss told the Nine Network he was pushed in the back after snatching a friend's hat back off the Melbourne Storm three-quarter.

"I didn't know it was coming," he said. "It was almost cowardly.

"I grabbed the hat and I was walking back to our table, which was the next table, and the next thing I know my back is thumping on the ground and I'm on the ground and all this stuff is going on on top of me.

"After the incident ... he was almost remorseful.

"He walked off to the side and had his head down. I think he knew he was in the wrong."

Chambers declined to speak when he entered the Maroons' training base on the Gold Coast.

The Nine Network reported teammates Billy Slater, Aidan Guerra, Ben Teo and Darius Boyd were out with Chambers at the Edward Street nightspot.

No punches were thrown during the scuffle and Slater reportedly pulled the parties apart.

The incident, which comes days after Cronulla star Todd Carney sacked for a lewd photograph taken at a urinal in a Sydney bar, has also been referred to the NRL Integrity Unit.

The investigation has put a serious cloud over Chambers' involvement in next Wednesday's dead-rubber at Lang Park and could continue his gut-wrenching run of being a "nearly man".

The 26-year-old, who played for the Queensland Reds in 2010-11, almost made the Wallabies in his two seasons of rugby union, and has spent the past two seasons on the fringes of the Maroons side.

Chambers was 18th man for game two in Sydney and his game three call-up had come after veteran winger Brent Tate badly injured his knee.

Queensland's Origin team has prior history at the Down Under Bar with coach Mal Meninga landing himself in hot water last year for going behind the bar to pour himself a drink.

The Queensland Rugby League issued a statement on Wednesday saying they were aware of an "alleged incident".

"The Queensland Rugby League (QRL) have been made aware of an alleged incident last night in Brisbane," the statement said.

"The League is currently working with the relevant authorities to determine the facts and will be making no further comment until this is complete. "

ABC/AAP