Palfreeman, now 33, was serving a 20-year sentence for fatally stabbing Bulgarian law student Andrei Monov, 23, during a brawl in the capital Sofia in 2007.

He was granted parole by a panel of three judges on Thursday, the ABC reported on Friday.

"I'm extremely pleased," Palfreeman's lawyer Kalin Angelov told the broadcaster.

"Surprised, in a very good way."

His father Simon Palfreeman said the family, from Newcastle, hoped to be reunited with him as soon as possible.

"It's a funny feeling, because I think it's been a long time coming," Dr Palfreeman told ABC.

"Of course he's not actually out yet, so we're still waiting for that to happen, but this decision can't be appealed so it's a very good decision for Jock."

His son claims he acted in self-defence in 2007 after intervening to prevent an attack on a Roma, or gypsy.

"It's a long, long story, but basically there was never any doubt in my mind that what Jock did on that night was to go help that young Roma boy that had been beaten," Dr Palfreeman said.

He said the most likely outcome was that his son would go into immigration detention, before being deported back to Australia.

"That's certainly what we're hoping for, but that will become clearer over the next few days," Dr Palfreeman said.

Earlier this year, Palfreeman went on hunger strike for 33 days in protest at the unfair treatment he suffered for his role in the Bulgarian Prisoners' Rehabilitation Association, the country's first prisoner advocacy union.

Angelov said the hunger strike was in response to Bulgarian authorities cracking down on the Australian for exposing corruption in the country's prison system and the abuse of inmates.

Australian Associated Press