Hull have beaten off competition from several Super League sides to sign London Broncos prop Lewis Bienek.
Bienek, 19, joins the Airlie Birds on a three-and-a-half year deal with immediate effect but will remain with the Championship side for the rest of this season on loan.
He said: “I chose Hull because I felt it would be the right environment for me. There’s some great players and outstanding facilities.
“Scott Taylor and Mickey Paea are two players who I look up to. They play very similar rugby to the style I like to play, and I’m looking forward to working with them.
“I was impressed with the success that Hull have had in the last two years, winning the Challenge Cup, and I’m hungry to enjoy some of that.”
Bienek, who stands at 6’2” and weighs 20 stone, made his first team debut in 2016 and played 13 times last season.
Coach Lee Radford said: “I’m really pleased to have secured the signature of Lewis, especially with the competition that we’ve had from other clubs in Super League and the NRL.
“I was very impressed with his honesty and the hunger that he has to be a successful rugby player. He’ll fit into our group very well with that sort of attitude.
“We’ve secured one of the best front row prospects in the British game and I’m very much looking forward to seeing him develop along with some of the talent that we already have in that department.”