The highly regarded 26-year-old, who can play scrum-half or stand-off, is being courted by Bradford Bulls, who want the Australian as part of their re-building plans.
However, Hull now seem certain to scupper that deal – and for less money than the Bulls are offering.
Having offered Seymour a contract, the Bulls were hopeful of securing his services, but an offer from Hull has turned his head.
It is understood the chance to join current team-mate Aaron Heremaia at Hull, plus the encouragement of former FC player Shaun Berrigan, has convinced Seymour his future lies at the KC and not Odsal.
A source, who has spoken to the player, has told the Mail Berrigan, now playing at the Warriors, has had a big role to play in Seymour’s decision.
With Heremaia already signed, FC believe the duo will hit the ground running and are trying to get a deal finalised after agreeing terms.
The player has been no stranger to controversy during a colourful NRL career, often hitting the headlines more for his off-field antics than performances on the pitch.
Now tee-total he has turned his life and form around at the Warriors.
Seymour’s arrival would be Hull’s third overseas signing for 2012, following Heremaia and full-back Wade McKinnon.