Australian Foreign Minister Julie Bishop has initiated formal diplomatic talks with Cambodia on behalf of the Australian filmmaker, James Ricketson, detained since last June.

Mr Ricketson could be imprisoned for five to 10 years after he was arrested on spying charges for flying a drone over political protests in the capital Phnom Penh.

Ms Bishop stated Australians and their diplomatic representatives should be vigilant to not do anything counterproductive in these circumstances, favouring “quiet diplomacy”.