A former staffer at Australia's embassy in Bangkok has been charged after multiple spy cameras were found in women's bathrooms at the mission, a Canberra official said Saturday.

Australia's Department of Foreign Affairs and Trade confirmed that Royal Thai Police had arrested a local former staff member last month.

"The welfare and privacy of all staff remains a priority for the department and we continue to provide appropriate support," a department spokesman said in a statement to AFP.

The spokesman declined to comment further on the ongoing legal matter.

Khemmarin Hassiri, commander of the foreign affairs division of the Royal Thai Police, said that the Australia embassy filed a complaint against a man on January 6. Thai police said the investigation was ongoing.

It's unclear how long the cameras had been in the bathroom, with the matter only coming to light after a camera SD card was found on the bathroom floor last year, according to a report by ABC Australia.

The incident represented a serious security breach, an Australian defence and foreign policy expert told AFP.

"If security was lax enough to allow devices like cameras to be installed anywhere within a secure area, it suggests it's not tight enough to keep the embassy secure," Hugh White, Emeritus Professor of Strategic Studies at the Australian National University, said.