A convicted murderer has been released from detention and spared deportation, with blessing of the mother of man he was jailed for killing.

Mark Basa was 16 when he was convicted of the 2005 stabbing murder of Zane McCready in Newcastle.

Over the past four years he has been in immigration detention, waiting in limbo as he fought deportation.

His father Richard Basa told the ABC he had no idea his son's release was imminent, when he got a phone call from his lawyer last Thursday.

"I was in shock — Mark's lawyer said get a car and get to Sydney, your boy is coming home to Newcastle," he said.

Mark Basa's lawyer, migration law expert Jason Donnelly, said he almost fell off his chair when he heard the news himself.

"I had to re-read that email about three times before I actually believed it," he said.

"(Mark and I) had a really nice personal talk over video camera and there were tears … of shock — but of great happiness."

A fight to remain in Australia

Mark Basa was convicted of killing Mr McCready, an Air Force technician, in a brawl in Newcastle in 2005.