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."

Read more: Jock Palfreeman's hunger strike in Bulgaria jail

In December 2009, Jock Palfreeman was found guilty of murdering 20-year-old Bulgarian law student Andrei Monov in the country's capital, Sofia, and sentenced to 20 years jail.

Jock argued he pulled a knife in self-defence after going to the aid of a Roma boy being attacked by Monov and a group of friends. But Monov's parents argued Jock was a sociopath who would kill again if released.

The 26-year-old was also ordered to pay about $375,000 in victim compensation, and has lost all avenues of appeal.

"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.

Dr Palfreeman has spent years hoping his son would be allowed to return to Australia.

In 2013, a book by ABC journalist Belinda Hawkins titled Every Parent's Nightmare, argued that vital CCTV evidence was kept out of court and crucial witnesses never called.

''Some of the information in the book would have been ideal if it had come out during the trial,'' Dr Palfreeman told the Newcastle Herald at the time. ''We want Jock's profile to stay high so we can continue to negotiate for his return.''

Ms Hawkins spent 40 hours with Jock at the Bulgarian prison while writing the book.

''He never asked me whether I thought he was guilty or innocent. We just talked,'' she said in 2013. ''He's a complex person. He would have been a handful as a child. He is very headstrong and very, very bright. He's full of life. He's enormously empathetic to people.''

Dr Palfreeman said on Friday 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," he 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.

While you're with us, did you know Newcastle Herald offers breaking news alerts, daily email newsletters and more? Keep up to date with all the local news - sign up here.

IN NEWS TODAY: