Wests Tigers general manager Mark O'Neill has resigned from his position after an investigation into allegations of inappropriate behaviour.

O'Neill's resignation comes after he was this month stood down indefinitely by the club over alleged misconduct following the club's final round loss to the Raiders.

The Wests Tigers announced his resignation on Friday afternoon.

"The Board of Wests Tigers is fully committed to ensuring the Club is an Equal Employment Opportunity employer and seeks to promote an environment that supports diversity, productivity and professionalism," the statement said.