The 33-year-old will face Sofia Supreme Administrative Court later this month, represented once more by his long-serving lawyer Kalin Angelov, to fight for his freedom.

"The government is saying they don't consider me free and therefore I can't leave Bulgaria," Mr Palfreeman told AAP.

"I expected this to happen as the Bulgarian state just doesn't have a rule of law unless outside countries push them.

"So when the Bulgarian state isn't pushed to follow their own laws, they don't."

The Sydney man was released on parole in September 2019 after serving nearly 12 years behind bars in the Balkan nation's capital.

He then spent one month in immigration detention and has since been able to walk freely subject to COVID-19 restrictions.

He was found guilty of murder and attempted murder for stabbing two Bulgarian youths during a street melee in 2007 but has always maintained he acted in self-defence.

Mr Palfreeman received a new passport from Australia earlier this year after Bulgarian authorities stripped him of the last one in 2019 but he remains frustrated at the official support he's received from home.

"Like my 12 years of prison and now another year after ... the Australian government has absolutely not done enough," he said.

A Department of Foreign Affairs and Trade spokeswoman said Australia has provided all necessary requirements to assist Mr Palfreeman to depart Bulgaria, when local authorities allow it.

"Officials are closely monitoring legal developments in his case and will attend his next court appearance, later this month," she said in a statement to AAP.

"It would be inappropriate to comment further while legal processes continue."

Australian Associated Press