A couple staying in an Airbnb called police after finding cameras and microphones hidden in two smoke detectors.
Derek Starnes and his wife were renting a holiday home in Longboat Key, Florida, when they made the horrifying discovery.
Police said Mr Starnes spotted an 'odd' black dot on the smoke detector directly above the bed in the master bedroom, and decided to take a closer look.
He realised it was a camera lens and found the recording equipment inside when he opened it up.
The same apparatus was inside another smoke detector in the living room.
Derek Starnes and his wife realised there was a hidden camera in their Airbnb
The couple, from Indiana, called police and the Airbnb owner Wayne Natt has been charged with video voyeurism.
Police have confiscated his computer equipment and found videos dating as far back as 2008.
Natt apparently told police the cameras were only for his own personal use when he hosted sex parties, and weren't activated when guests were staying.
Wayne Natt said he used the cameras to record sex parties he hosts at his house
But police confirmed they were operated remotely.
"Our question is, if people are aware the cameras are there, why are they hidden in smoke alarms? And his answer was – for a better angle," said Lieutenant Robert Bourque.
The officer said he is concerned many more people may be victims of Natt's voyeurism and asked anyone who is worried to come forward.
"I suspect there are other victims, it's just a matter of identifying them or not," said Lt. Bourque told WFLA.
"Who knows what it's been used for."
Meanwhile, Mr Starnes said he and his wife have been left "distressed" by what happened.
He said he is certain the camera captured him naked before he realised it was there.
An Airbnb spokesman told the channel: "We are outraged at the reports of what happened; as soon as we were made aware, we permanently banned this individual from our community and fully supported the affected guests.
"Our team has reached out to local law enforcement to aid them with their investigation of this egregious offence and we hope justice is served.
"We take privacy issues extremely seriously and have a zero-tolerance policy against this behaviour."