Reigning Man of Steel Ben Barba will not be welcome back in Super League if he is banned by the NRL, the Rugby Football League has warned.
The 29-year-old former St Helens full-back, who was the leading try-scorer in Super League in 2018, was sacked by his new club, North Queensland Cowboys, without playing a game over an alleged assault on his partner outside a Townsville casino.
The incident is being investigated by Queensland police and Barba looks likely to be banned for life by the NRL.
If that happens, the Rugby Football League say it will uphold the suspension, blocking a route back to Super League.
An RFL statement said: "We will always uphold any ban imposed by the NRL (subject to the right of appeal to our own operational rules tribunal), under a reciprocal agreement between the RFL and the NRL.
"Independent to that arrangement, the RFL board has the right to refuse registration to any player - and would also consult with Super League in that process.
"We are bound to follow that process - but, if the facts of this case turn out to be as reported, the RFL would condemn them as deplorable."
The RFL rejected an appeal by St Helens against a 12-match ban imposed by the NRL on Barba for cocaine use in the aftermath of Cronulla's 2016 NRL Grand Final triumph.
Sacked by Cronulla, Barba had a brief spell in rugby union with French club Toulon before being snapped up by St Helens in May 2017 in the face of competition from Warrington.
He was restricted to playing the last five matches of the season for Saints, but made up for lost time in 2018 when he was named in the Super League Dream Team and became the first player to win both the Dally M Medal and Man of Steel.
Barba was then released from the final year of his contract with Saints after he was handed a chance to resurrect his NRL career with the Cowboys, who on Friday announced they had terminated his contract due to a "significant breach of the terms".
He had been named in the Indigenous All Stars team to play the New Zealand Maori in the NRL's traditional season pipe-opener on February 15, but now faces a bleak future in the game.