Sale Sharks have secured the signature of rugby league convert Denny Solomona on a three-year contract.
Solomona is under contract with Castleford and the Tigers and the Rugby Football League are deeply unhappy about the move, with legal action possible.
The Auckland-born flyer scored 42 tries for Castleford in 2016, breaking Lesley Vainikolo's Super League record set in 2004 and Sale could use him at full-back, wing or in midfield.
Sale Sharks Director of Rugby Steve Diamond said: "We are delighted that Denny has signed for us. He is a great player with an eye for scoring tries and has the added bonus of having played Rugby Union in his time at school and college."
The RFL recently revealed their support for Castleford over the contract row with Solomona, with the Tigers preparing for a high-court battle after the 23-year-old winger failed to turn up for pre-season training amid rumours of a switch of codes.
RFL chief executive Nigel Wood said on December 6: "The RFL is extremely disappointed to learn that properly contracted Super League players may not be fulfilling the terms of their employment with Super League clubs as agreed.
"Contracts are two-way commitments mutually binding on both parties. The RFL will support its member clubs absolutely to defend their contractual positions and will work with other similarly inclined governing bodies to ensure that the unacceptable potential anarchy of lawful contracts simply being walked away from, is not tolerated."
Castleford, who have said they rejected three offers for Solomona, have appointed leading London barrister Nick Randall QC - whose other clients include England captain Wayne Rooney - and Leeds-based sports lawyer Richard Cramer to fight their case.
The RFL is also investigating the actions of Solomona's agent Andy Clarke.