Israel Folau could face legal action from French side Catalans Dragons, following Friday's announcement that he's signed with Gold Coast's Southport Titans.
Folau, 32, has partnered with Australian billionaire Clive Palmer - a patron of Southport Titans - signing for the club in an attempt to resurrect his career in his homeland.
But Folau is still contracted with Catalans through until the end of 2021, having joined the French UK Super League side in 2020.
The sacked Wallabies star was granted compassionate leave by Catalans, and returned to Australia to be with family.
But after hearing news of Folau's attempt to join another club, Catalans say they had no knowledge of the moves, with the former Wallabies and Kangaroos international still on their books.
"We still hold his contract, he's still a registered player with Catalans Dragons. It was a big shock to see what was put out there," Catalans' football manager Alex Chan told PA.
"We can't just let things happen like this. I've got to meet with the club president and our directors but I've already made our legal team aware of the situation that is starting to unfold.
"We need to start being proactive from our end in case things start to escalate and go nasty."
Fronting on Friday, Folau's billionaire backer Palmer said he's prepared to put his considerable resources into any legal battle to ensure the cross-code star can turn out for Southport.
Folau still needs the sign off of Queensland Rugby League before he can turn out for Southport, and the governing body said that it was considering the move "in line with its rules and processes that govern the registration of players".