A McDonald's restaurant in Christchurch has defended the use of surveillance cameras in its toilets.

McDonald's in Linwood is hoping to deter vandals, by positioning a CCTV camera above the wash basin and mirrors.

The camera is not directed at the urinals. However, a customer told Newstalk ZB they felt it was an invasion of his privacy, fearing his image could have been projected onto the mirror.

Customer Nicholas Case said he didn't notice signage pointing out the camera until he went to wash his hands.

"If I had of seen the sign before that I would have gone into the cubicle or something," he said. "It was a bit of a shock to see that there was a camera watching what I was up to in the toilet."

"If the camera was looking at the main door you walk in, then that would be alright. But the fact that it's looking at the mirror, your face is in the mirror while you're at the urinal."

A spokesperson for McDonalds says the aim of the camera is to help manage the safety of customers and staff - and it's not the only McDonald's restaurant in the country to make use of CCTV cameras in the bathrooms.