An Australian filmmaker accused of spying in Cambodia has called upon the federal government to defend his right to free speech after a Phnom Penh court postponed his appeal for bail.

No reason was given for the delay in the James Ricketson case on Wednesday.

A court official said his appeal to be released on bail would be resolved on 31 January.

Ricketson arrived handcuffed and in prison overalls after the postponement was announced.

Speaking to reporters outside the court he said: “I’d like to know which country I’m spying for.

“Journalism is not a crime. I have the right free speech under the Cambodian constitution. I’d like to think the Australian government would defend my right to free speech.”

Ricketson, 68, was arrested in June and charged with “collecting information prejudicial to national security”. He faces five to 10 years if convicted.

Since his arrest, Ricketson has been confined in Cambodia’s notorious Prey Sar prison, where he has been kept under tight security.

Cambodian friends have also told local media that he was being kept in an overcrowded cell and was in need of medical attention for high blood pressure, lice, scabies and inflammation of the legs.

The partner of Ricketson’s son, Alexandra Kennett, said outside the court that Ricketson’s family was hoping for a swift conclusion and was disappointed with the delay.

“Its obviously difficult for the family every time we are in court and disappointing to have this delay come about today,” she said. “We just ask that the evidence be brought forth and that bail either be accepted or denied so that we can continue to move forward.”

Ricketson high-profile case is winning international attention, with his arrest made amid an unprecedented peace-time crackdown on dissent in Cambodia.

A petition calling for his release and asking the Australian government to do more has attracted more than 50,000 signatures, Kennett said.