Nielsen controversially made the move to England after St George Illawarra tore up his contract following an incident in a nightclub in Sydney in which it was alleged he bit a woman’s leg whilst drunk.
Nielsen made just five appearances for James Lowes’ side, including the 24-16 Million Pound Game defeat to Wakefield in October.
The centre had agreed a new deal at The Provident Stadium until the end of the 2016 season, but Bulls managing director Steve Ferres has revealed that he has departed from the club.
“Dane will not be playing for us in 2016. We have taken the decision not to extend his contract for a second season,” Ferres told the Bulls’ official website.
“We thank him for his contribution last year and wish him well for the future. This allows us to explore further options for 2016.”
The 30-year has made more than 100 appearances in the NRL and represented Queensland three times.
It is believed Nielsen plans to return to Australia.