Hull FC have confirmed Huddersfield half-back Jake Connor has signed a contract to join them from 1 December.
Reports had suggested Connor was considering a new contract with Giants after they offered improved terms.
Connor agreed to join Hull FC in June, but was waiting after his 22nd birthday in October to complete the move.
Rugby league teams are entitled to compensation for players under the age of 22 who sign elsewhere having been offered terms at their current club.
In a statement, the club said: "The contract, which is signed by both the player and the club, was lodged and accepted by the Rugby Football League.
"This contract is legally binding and states that the player has signed for Hull FC and will join the club from the 1 December 2016 in preparation for the new season.
"If the contract is not fulfilled for any reason then the club will have to pursue legal proceedings for breach of that contract and for the inducement of that breach."