If you see this hook call the police

Plastic hooks may seem harmless, but a certain type can be very sinister. 

Police have warned about a particular type of hook that perverts are purchasing online that contains hidden cameras inside. 

They install these hooks in public toilets, hotels and changing rooms to spy on people, NBC reports.

If you see one, the police advise you to report it straight away.

Similar hooks are available for $45 on TradeMe.

They look like any other ordinary hook, but include a small dot at the top which houses a tiny cameras lens.

The concealed hook cameras are battery-operated with a small memory card, and can be mounted anywhere.

Florida Keys sheriff Rick Ramsay has told the Miami Herald that anyone who had a public restroom on their property needed to check them closely.

"Keep in mind, though, that these are very small cameras that can be mounted in many locations and hidden in many seemingly everyday items."