A spate of high-profile incidents have showcased just how easy it is for Airbnb hosts to spy on unsuspecting guests.

When Tony Greathead shook hands with the female guests of his New Zealand Airbnb homestead last year, he presented himself as a good family man – someone they could feel safe staying with.

Most of the guests were women and Greathead, a former prison officer who lived with his wife and two children, organised times for them to use the main shower in the house.

Over three months he filmed 34 female guests as they showered, with covert cameras he placed in shampoo bottles. Eleven of the videos were uploaded to an adult site, with one of the videos viewed more than 7000 times.

In October, Greathead pleaded guilty to 51 charges and was sentenced to four years and four months in prison.

On rare occasions, guests have found hidden cameras. Photo: Getty

While most guests leave Airbnbs with little to complain about, on rare occasions their stays have been disturbed by finding hidden cameras secretly filming them.

Last week, a family from New Zealand discovered a camera hidden within a smoke detector live streaming from the lounge room of a property they were renting in Cork, Ireland.

In March, a couple staying in California found one above their bed.

And it’s not just Airbnb. Earlier this year, four individuals were arrested in South Korea for a scheme allegedly involving placing cameras in 42 motel rooms across the country, broadcasting the videos to more than 4000 viewers.

These cameras are cheap, easy to use and hard for guests to find, says Julian Claxton, managing director of counterespionage organisation, Jayde Consulting.

Hidden spy cameras can be bought online for as little as $37.99. Photo: Amazon

“Depending on how well they’re hidden, it can be very difficult to detect them without professional help,” Mr Claxton told The New Daily.

“The devices are really easy to get. If you type in ‘hidden camera’ into eBay you will get thousands of hits. The new ones, they’re building them into charger packs, into the bases of lamps, clocks, radios – you name it and you can put a camera in it.”

Those hiding cameras in hotels are looking for more specific targets, Mr Claxton says.

“Often it’s not the hotel themselves, it’s a rogue worker who is more interested in a perversion or extortion,” he said.

“For instance, if you work for a major conglomerate and have a dalliance with a man or woman while you’re married, that video can then be used to extort that person.”

Australian Security Industry Association Limited general manager John Fleming says the fact the laws change between states and territories makes it a complex issue.

“Every state and territory has its own privacy and surveillance act, but the bottom line is anything hidden is illegal. To hide a camera legally you need a magistrates order,” he told The New Daily.

“It depends how it’s used. You can use small cameras for childminding. What purpose is it used for, that’s the key element.

“If you’re secretly recording in your Airbnb you’re doing something deceptive. If someone hasn’t notified the tenants and has been using the video for their own pleasure, that’s illegal.”

So what do you do if you find a camera?

If an unsuspecting traveller does come across a camera, they should call the authorities, Mr Croxton says.

“My recommendation is to contact the authorities. That is the first thing they should do. Don’t touch it [as] that could contaminate the evidence,” he said.

“But you’ve got to remember the majority of people are good people. It’s really important to state we must not be paranoid.

“It’s a select few who are dishonest or corrupt. There’s no reason to run into panic mode.”

Airbnb did not respond to questions from The New Daily.