PHNOM PENH, Cambodia — An Australian filmmaker on trial in Cambodia on charges of endangering national security defended himself Thursday under cross-examination, declaring the evidence shows he is a journalist, not a spy or political operative.

James Ricketson was arrested in June last year after he used a drone to film a rally of an opposition political party ahead of local elections. The charge against him is tantamount in legal terms to espionage, punishable by up to 10 years in prison.

He said in Thursday's testimony that his filming of the opposition Cambodia National Rescue Party was strictly journalism, and that video and messages presented as evidence by the prosecution were the products of journalism, not spying.

The political party was dissolved last November as part of a sweeping crackdown on the opposition and media critical of Prime Minister Hun Sen's government ahead of last month's general election, in which the ruling party won all 125 National Assembly seats.

Ricketson, 69, has been held in a crowded prison cell since his arrest, with several appeals for bail denied.

He was seen as sympathetic to the opposition, a charge he disputed in court.

Ricketson admitted having had contact with former opposition leader Sam Rainsy but denied he worked for him, saying such contact was the nature of journalism.

Prosecutors showed the court an email Ricketson sent to his lawyer and to the Australian prime minister detailing Hun Sen's security capabilities and the strength of his bodyguard unit.

Ricketson replied that this information was widely known to any journalist in the country, and if it was not true, he should be charged with being a "careless journalist," not a spy.