St George Illawarra's glut of halves forced the Dragons to release Josh Drinkwater from the final year of his contract.
The 21-year-old, a boom National Youth Competition halfback with Manly, was touted as the Dragons' answer to their long-running halves dilemma when he joined the Red V last season.
But after he struggled in his first season in Wollongong, featuring sparingly in just four NRL games off the bench and even sent back to the Illawarra Coal League at one stage, Drinkwater was granted an escape route via the English Super League.
He will join the London Broncos immediately.
"Josh has received a good offer and opportunity to play in the Super League and we respect and understand his desires to take up this opportunity," said Dragons coach Steve Price.
"We thank him for his services and contributions to our club and wish him well for his future."
The Dragons snapped up former London Broncos half Michael Witt to bolster their playmaking depth and Drinkwater is likely to be a direct replacement.
The Dragons also released Jamie Soward to the Super League club midway through last season.
Price used Canberra recruit Sam Williams, Witt and even utility Kyle Stanley at halfback against Souths on Saturday night.