Castleford have confirmed the signings of Hull KR centre Jake Webster and Hull scrum-half Jamie Ellis.
Former New Zealand international Webster, who arrived at the Robins in 2008 from the Gold Coast Titans, will join the Tigers on a three-year contract at the end of the current campaign.
He is the second centre to be snapped up by the club, Castleford having also secured the return of England international Michael Shenton from St Helens.
"I was looking for a specialist centre with experience and Jake ticks both boxes. He is a damaging runner and can create fear in opposition's attack with his defensive qualities," Tigers coach Ian Millward said.
"I believe the paring of him and Michael Shenton, two specialist international centres, will be up there amongst the best in Super League next year."
Ellis, meanwhile, will be reunited with his old Leigh boss Millward at the PROBIZ Coliseum after agreeing terms on a two-year contract.
He joined Hull at the end of last season but has made just 10 Super League appearances and was given permission to talk to other clubs on Monday.
"Jamie is a player I think has an abundance of talent," added Millward.
"He has a wonderful kicking game and is a player who has played regular Super League with Hull this year.
"He reminds me very much of an Australian-style half-back who likes to take the ball to the line."