BELFAST, Maine — Last week, the Belfast Police Department used the power of social media to reunite two people with a camera they had lost two and a half years ago.

It all began, according to Sgt. John Gibbs, when a woman called to ask if anyone had turned in her lost car keys.

“I started digging through the lost-and-found box,” he said.

He didn’t find the car keys, but he did spot something he hadn’t before — a Pentax waterproof camera that was being stored in a plastic bag filled with loose tobacco. It was a mess, but Gibbs got curious and cleaned it up, taking out the camera’s SD chip and putting it in his computer to see if there were photos on it.

There were, hundreds of photos, some of which showed smiling people posing in tropical fields that clearly were not in Maine. Officers had made an effort to find the camera’s owner in 2012, but weren’t successful, Gibbs said.

So he decided to see if any of the department’s 4,000-plus Facebook fans knew any of the people in the photos. Within an hour, he had a hit when one woman recognized her friend’s brother and his girlfriend. The Yarmouth couple thought the camera had been stolen out of their car. They didn’t realize it had been left behind on a rock, and that an honest passerby had brought it to the police.

Some of the photographs were taken on a trip to the Central American country of Nicaragua.

“Thank you so much, ‘Belfast Police Dept.’ and especially Sgt. Gibbs, for going out of your way to return this camera. There are so many wonderful memories that I’ll be delighted to have back,” one of the owners wrote on the police department’s Facebook page. “The time that was spent finding its home is well appreciated! Thanks again.”

BDN efforts to contact the couple were unsuccessful.

Gibbs said that the police officers have a petty cash fund they replenish with money from redeeming their bottles and cans. He used the fund to mail the camera down to Yarmouth.

“I’m just glad they got it back,” Gibbs said.