Wests Tigers premiership winner Mark O'Neill has been stood down indefinitely from his role as the club's football general manager pending an investigation into alleged misconduct.

Fairfax Media understands the Wests Tigers are investigating allegations of inappropriate behaviour ​involving O'Neill and a colleague and he has been asked to remain away from the club's Concord headquarters until the investigation is complete.

Under investigation: Wests Tigers general manager of football Mark O'Neill. Credit:Dallas Kilponen

The Wests Tigers have informed the NRL integrity unit of allegations but the governing body believes it is a matter for the club to resolve.

Tigers chair Marina Go confirmed there was an investigation into the alleged misconduct.