He said: "We're innocent-minded people but the clock was facing where our bed was and we thought it might be for something more sinister like a sex ring".
"We booked a one night stay in a lovely apartment in the centre of Toronto for last night (September 6)".
"We were only in the place for 20 minutes when I noticed the clock", Mr Hamilton, from Glasgow, told the Daily Record. After a busy day in the city, he and his girlfriend settled in for a relaxing night - or so they thought.
Hamilton had recently watched a YouTube video on secret "spy" cameras and how they are often found concealed in ordinary, everyday, household objects.
After removing the clock's charger and discovering a lithium battery in the back of the device the front face of the clock cam off and revealed the camera. There was just something in my head that made me...
Because of the video he had seen, he made a decision to be the "crazy guy that checks a digital clock for cameras", and he was surprised by what he found.
Hamilton alerted both Airbnb and the police in Canada, who are now investigating the incident.
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"It was connected to a wire like a phone charger which wasn't quite right".
"Airbnb passed it on to their security team".
Hamilton lodged a complaint with Airbnb and the accommodation site told him it would launch an urgent investigation.
Hamilton said the clock faced the bedroom and living room and "could see everything".
However, according to a report from the Daily Record, the owner of the apartment in Toronto owns six other properties and has racked up hundreds of positive reviews.
Airbnb gave the couple a full refund and found them alternative accommodation nearby. He added that police have yet to interview the owner of the apartment, which he said is located "somewhere in and around King St".
"We have removed the host from the platform while we investigate and are providing the guest with our full support".