The NRL's integrity unit are working with World Cup officials as Sydney Roosters star Victor Radley is investigated over an alleged fracas with an Irish player.
Radley, who played for England in the World Cup, is at the centre of allegations of a hotel altercation with Ireland international James Bentley.
The Roosters lock was part of a group of England players still at their Manchester hotel on Monday after their 27-26 semi-final defeat at the hands of Samoa in London.
Bentley was invited to the England hotel where a number of the squad's NRL-based players were staying before returning to Australia.
Sources with knowledge of the incident have told AAP Radley was not the instigator of the incident.
Instead, the altercation came after verbal abuse directed at England coach Shaun Wane over Bentley's non-selection in the national squad.
After Bentley was asked to leave, he and Radley are understood to have become embroiled in an argument.
"The NRL Integrity Unit is aware of the matter and liaising with Rugby League World Cup officials," an NRL spokesman told AAP.
England's Rugby Football League are also investigating, with Bentley a part of Leeds' Super League squad that reached this year's grand final.
"The RFL have been made aware of allegations and are currently investigating the matter," they governing body said in a statement.
Radley's selection in the English squad was a controversial one, given he is Australia-born and based.
However the 24-year-old made the call to give up potential future NSW State of Origin representation by honouring his father's heritage.
It is not the first time Radley has found himself in hot water.
He was suspended for two games at the start of 2021 for an incident in Byron Bay, although again it was claimed he was not the instigator of the situation.
He was also told by Roosters coach Trent Robinson midway through last year it was time to grow up and "act like a man in public" after being removed from a plane over alleged drunkenness.
The lock insisted he had heeded the message earlier this year, desperate to clean up his on-field and off-field act after a 2021 littered with suspensions.
"The last two years I haven't played as much as I would have liked to," Radley said in March.
"I spoke last year about how I wanted to be a leader, and I didn't really do that."