St Helens have suspended scrum-half Kyle Eastmond pending an investigation into "serious misconduct".
A statement from the club said they will be making no further comment until the completion of the investigation.
The 21-year-old will switch codes at the end of the Super League season to join rugby union side Bath.
In February, Eastmond was forced to apologise to Saints fans for leaving the pitch immediately after the 25-18 defeat by Warrington.
A product of the St Helens youth system, Eastmond made his first-team debut in 2008 and has played a total of 62 games, scoring 417 points.
His form prompted Saints to allow long-serving Sean Long and rival scrum-half Matty Smith to leave the club.
Eastmond made his England debut against Wales in 2009 and he was handed the number seven shirt at St Helens for the 2010 season, but an injury-disrupted campaign resulted in him missing the Grand Final defeat by Wigan and the Four Nations.
His recovery from ankle surgey was quicker than expected, allowing him to play in all five of Saints' Super League matches so far this term.
But amid speculation about his impending cross-code switch, Eastmond was left out of the 32-man England elite squad in February.
His move to Bath was confirmed at the beginning of March, with Eastmond saying at the time: "St Helens have been fantastic with me since I joined them 10 years ago and I am deeply indebted to them for their amazing support.
"I intend to give everything to the club, its supporters and my fellow players in my final season."
Saints, who currently lie seventh in Super League, will now have to do without Eastmond for Saturday's trip to Leeds, with Gary Wheeler expected to take his place.