Hadley, like a number of Widnes player, is owed money and said: "Widnes haven't honoured my contract and I'm not prepared to accept the situation any longer. I have played my last match for them."
Hadley, who is recovering from a knee injury has been linked with a return to his old code at the age of 32. But he says that he has had no approaches and may retire.
The club's chairman, Jim Mills, said that he was disappointed by Hadley's decision, but promised that players will be paid before Christmas.
Another Welshman, Scott Gibbs, has been passed fit to return for St Helens in their Regal Trophy quarter-final against Halifax on Sunday. Saints have told Welsh clubs they are wasting their time trying to entice Gibbs, who replaces the cup-tied Paul Newlove, back to union. The Western Samoan captain, John Schuster, will miss that match and could be out until the new year after breaking his thumb.
Kevin Ellis has offered his services to his former club, Warrington, who have their first-choice scrum-half, Mike Ford, with a hamstring injury, while his predecessor, Greg Mackey, is due to retire and fly home to Australia next week.
Wigan have been invited to take part in Bristol rugby union club's sevens next May.Reuse content