Australian Jock Palfreeman is a step closer to freedom after Bulgaria’s highest court dismissed an appeal against his release.

After a months-long delay, The Supreme Court of Cassation dismissed the unprecedented appeal against Palfreeman’s parole as invalid and unlawful on Thursday.

“The request for reopening of the case is procedurally inadmissible and should be left without consideration and the proceedings should be terminated,” the judges’ ruling said.

The court said its decision cannot be appealed.

However Palfreeman, 33, says he has not made any plans to leave the country as the Bulgarian government is still controlling his movements.

“I don’t have any plans now because I am not in control of my life,” Palfreeman told AAP.

“I am out of prison but very much still at the whim of the government.

“The government has refused to allow me to leave despite it not being legal, and so there is no movement on allowing me to leave or not, and this decision doesn’t change that because my being kept in Bulgaria isn’t based on law.”

Bulgaria Helsinki Committee president Dr Krassimir Kanev, who wrote a letter in support of Palfreeman’s early release, said the court’s decision was a “major step” towards his freedom.

“Jock’s return back to Australia is a matter of time now,” Dr Kanev told AAP on Thursday.

“These past nine months have been a huge stress for Jock and his family.

“They must feel relieved now, as I do.”

The Sydney man was released in October after serving nearly 12 years behind bars in Sofia.

He was found guilty of murder and attempted murder for stabbing two Bulgarian youths during a street melee in 2007.

Palfreeman has always maintained he acted in self defence.

He called for Bulgaria’s former chief prosecutor Sotir Tsatsarov to resign as head of the country’s corruption watchdog after Thursday’s decision.

Tsatsarov lodged the appeal against Palfreeman’s parole.

“It is clear that he is compromised and did not fulfill his duties as required by the law,” Palfreeman told AAP.

“He abused his office and abused the grief of the family of the deceased to deceive the entire country, and that means he is compromised and can no longer credibly head Bulgaria’s anti-corruption body.”

Meanwhile, the former student of St Ignatius’ College Riverview is waiting for a ruling on his lawsuit against Bulgarian prison authorities for keeping him in “inhumane” conditions.

Palfreeman founded the country’s first advocacy union, the Bulgarian Prisoners’ Association in 2012, and hopes his high profile case will have a knock-on effect.

“The more people sue over bad conditions, the more we hope to improve them,” he said.