A Korean couple traveling in Japan found a hidden camera disguised as a fire detector in a house rented through Airbnb.

The couple, according to a post they uploaded to an online community, said they spotted a green light coming from a fire detector in a corner of the room as they were readying themselves for bed.

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A Korean couple found a suspicious-looking fire detector installed in the corner of the Airbnb house they rented for their Japan trip.(Online community via The Korea Herald/File)

The detector appeared to have a tiny camera lens pointing directly toward the bed.

The couple talked about what would happen if the detector were actually a hidden camera. Things went downhill from there.

A green light came on in the device, with what appeared to be a camera lens pointing toward the bed.(Online community via The Korea Herald/File)

“The night became a nightmare after we searched online and found an exact same-looking cameras up for sale on the internet,” the Korean man wrote online.

Shocked, they disassembled the fire detector and found a micro-SD memory card inside. The card turned out to have recorded everything that had happened in the room.

The couple disassembled the device and found a micro-SD card with footage of them inside the house after entering the room. The footage was recorded in one-minute intervals.(Online community via The Korea Herald/File)

“Fortunately we hadn’t done anything that night, but this was an Airbnb house we had previously rented on an earlier trip,” the distressed man said.

The couple contacted the South Korean Embassy in Japan for help in reporting the case to police.

“People from the embassy came to the police station to offer support. They drove us to different accommodations to stay at for the remainder of the trip,” the man wrote.

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The couple searched online and found similar-looking clandestine cameras openly for sale.(Online community via The Korea Herald/File)

A representative from Airbnb told The Korea Herald that “Airbnb has a zero-tolerance policy towards privacy infringements” and that “any relevant cases are dealt with utmost gravity.”

The host of the home fitted with the alleged hidden camera was immediately banned from the Airbnb community and maximal support was given to the guests.

Pinhole-sized camera.(Online community via The Korea Herald/File)