The 20-year-old Great Britain forward, who played in all three Tests against Australia this month, still has four years of his contract to run and his club said it would allow him to leave "very reluctantly."
Wigan have been regarded as favourites to sign him, but their offer of players in exchange does not appeal to Warrington. London displayed their interest by saying they would fly him to the capital by helicopter for talks, while Bradford are also in contention.
Sculthorpe's age and quality make him at least as valuable as his former team-mate, Iestyn Harris, who went to Leeds for an estimated pounds 350,000 earlier this year. If a three-cornered auction develops, the record pounds 440,000 that Wigan paid Widnes for Martin Offiah in 1992 could be under threat.
Meanwhile, Keighley, one of the best-supported clubs in the lower divisions, and Workington, who were in Super League during its inaugural season in 1996, could both be expelled from the league after being in administration for more than a year. Along with perennial strugglers, Prescot, they could face being thrown out unless they can come up with convincing business plans before next Wednesday, when the Rugby League Council meets.
A midsummer break from domestic competition for next season will also be considered then, with a triangular tournament in Australia, also involving Great Britain and New Zealand, being one possible option to fill the gap.
At the same time, a home international series would be played in Britain, but the World Cup, scheduled for Australia next October, would be postponed.
- Dave HadfieldReuse content