St George Illawarra have announced Melbourne Storm front-rower Patrick Kaufusi will join the Dragons for the remainder of the season.

The Tongan international and former Queensland Under-20s representative has played 25 NRL games to date across stints with North Queensland and Melbourne.

Kaufusi played 22 games for the Cowboys in 2015-17 before a season-ending foot injury derailed his final season at the club, where he played the first nine rounds. He joined the Storm in 2018 where he featured three times.

"Patrick is a welcomed addition to our roster for 2019, he's a quality person from a tremendous squad and system," Dragons Director of Rugby League Pathways and List Management Ian Millward said.

"He's a player capable of playing in the middle and back row, who is keen and willing to play first grade.

"With the current spate of injuries in the team, it's a really good opportunity for Patrick and the Dragons to see what impact he can bring to the club and playing squad. From there, we can consider our options with him for the 2020 season."

A positional equivalent to Jack de Belin as a middle forward, Kaufusi fits the NRL's criteria for salary cap dispensation and will fill the Dragons' 30th roster spot as required before June 30.

"You don't replace a player of Jack de Belin's calibre with ease, particularly midway through the season," Millward said.

"This entire process and circumstance has been extremely complex. It is complicated by not only the rules and regulations but also by the existing injury toll across the competition. This means clubs are unwilling to release players, as the representative period is back in full swing too.

"There has also been no clarity over salary cap dispensation for 2020 or when a determination of Jack's matters will be reached, which makes it very difficult to both accurately plan as a club and offer prospective players any certainty beyond 2019 – particularly with 23 players already under contract for next year.

"It has been a lengthy process to get to this point but we are pleased we have been able to come to this arrangement with Patrick and the Melbourne Storm."

The current NRL development player squad will also become available for first grade selection post-June 30. The Dragons' 2019 development players are Eddie Blacker, Jackson Ford, Hayden Lomax, Joe Lovodua, Steven Marsters and Jason Saab.

Kaufusi will arrive for St George Illawarra Dragons training this weekend.