Commodore Alfred Keating has been charged with attempting to make "an intimate visual recording" and is currently on trial in Auckland, local media reported.

According to court documents, Keating is alleged to have installed a small camera "in a unisex bathroom on Level 3 of the New Zealand Embassy" in the US capital in 2017.

"It had been purposely mounted inside a heating duct unit in the bathroom," and was only discovered when the panel fell to the floor.

The embassy employed around 60 people at the time.

"A thick layer of dust on the homemade platform the camera was mounted on indicated the device had been in place for many months."

The camera's media card had traces of Keating's DNA and his computer contained the camera's driver and related software.

Ahead of the trial, Keating tried to prevent the public from knowing his identity, arguing it could make it "difficult to obtain future employment" and sully the military's image.

A judge rejected that application. Keating has pleaded not guilty.