Broncos' football manager Robbie Moore said: "We were waiting for clarification of the legal position and now that the player has to return to this country we will be making further inquiries. We are always interested in acquiring top-class players."
The London side have been tracking the 6ft 7in Mather since he was placed on the transfer list by Wigan for pounds 150,000 last November after a contract dispute. The Central Park club maintain that he is under contract to them until 1997.
Lawyers acting for the 22-year-old, who was a member of England's World Cup squad in October, had been trying to free him from his registration with Wigan so that he could join the Australian club Perth Western Reds in March.
Broncos, without a coach since parting company with Gary Grienke on Tuesday, will be without the services of the England winger Ikram Butt for their Challenge Cup visit to Dewsbury tomorrow.
The former Leeds and Featherstone player had a groin operation this week and will be out of action for about six weeks. He hopes to return for the start of the Super League season.
A Scottish consortium are attempting to wrest control of Super League club Workington Town. Bob Jamieson and his business partner Angus Cook had been involved in an attempt to launch rugby league in the borders at Galashiels during the summer. Jamieson is working for three months as Town's marketing director and Cook, a property developer and former director of Dundee FC, have pledged to put money in the club if they get control.
However, the Workington directors are also talking to two business groups from Cumbria and hope to reach a decision early next month. "We need short- term inward investment and we are looking for a figure to do for us what Jack Walker did for Blackburn and Sir John Hall for Newcastle," Kevan Gorge, the club chairman, said.
The club have transfer-listed the prop Garry Schubert at pounds 10,000 after he was unable to agree a new contract for the Super League.Reuse content