Final court questioning over espionage charges was unexpectedly delayed today for jailed Australian filmmaker James Ricketson.

Ricketson, 68, said he was “cautiously optimistic” as he disembarked from a prison van at the Phnom Penh Municipal Court on Tuesday morning.

He was expecting a fourth round of questioning from investigating judge Pich Vicheathor before the session was postponed at the last minute.

Ricketson’s lawyer, Peung Yok Hiep, said a new date had yet to be announced and today’s questioning was postponed because the judge had an “urgent meeting”.

Speaking over the heads of other prisoners in a crowded room, Ricketson claimed he had contracted scabies in a crowded cell of 140 detainees and expressed hope that the Australian authorities would do more to help him. Australian Foreign Minister Julie Bishop has written to her Cambodian counterpart regarding his case.

Ricketson was arrested in June last year after he flew a drone above an opposition party rally. He was charged under Cambodian espionage laws and faces up to 10 years in prison if convicted.

He has remained in prison for nearly 9 months without trial and his appeals for bail have been rejected.

Investigators are combing through more than 20 of his emails to foreigners, friends, journalists and former opposition leader Sam Rainsy. Three of those emails, seen by the Post, appear to contain only routine correspondence.

Australia’s national broadcaster, the ABC, reported seeing the contents of a dozen of Ricketson’s emails and said they showed “a strongly worded dislike of Prime Minister Hun Sen and enthusiastic support for the opposition but nothing remotely akin to spying”.

Ricketson has proved a divisive figure during his years in the Kingdom. While he has won praise for his personal charity towards Cambodia’s poor, he had also been embroiled in defamation suits and controversially campaigned for the release of a convicted pedophile whom he believed was innocent.