The cheeky voyeur was caught red-handed on a beach in the Andalusian town of Benalmádena on Friday.

One beachgoer alerted local police after he spotted the man wearing a pair of outlandish shades which he was constantly adjusting.

The irate nudist held the suspect down until officers were at the scene, local daily Diario Sur reported on Thursday.

When questioned, the 48-year-old admitted he’d been filming naked women along the beach with his “spy shades”, which had an adjustable lens in the middle of the frame.

Police, who arrested the voyeur for invasion of privacy, found a video camera, a regular camera, a pen drive and half a dozen memory cards in the man’s beach bag.

The news comes as privacy concerns are being voiced about the impending arrival of Google Glass.

The tech giant has been under scrutiny over the issue of people being secretly filmed or photographed with this new wearable computer.

But Google has talked down concerns by saying the new software requires users to give an explicit command such as “Glass, take a picture”.

The high-end device will also light up when the camera or video are activated.

Google Glass prototypes are currently on sale for €1125 ($1500).