When Kevin Hayes's treasured camera was stolen while he was on a business trip in Canberra in March 2009, he didn't hold out much hope of getting it back. The theft was galling both because the camera was a birthday present from his wife four weeks before – and that its A$5,200 (£3,400) value wasn't insured.

More than two years later, after Hayes happened to mention his loss on a web forum, someone suggested he take a look at a website called StolenCameraFinder.com. The site was set up in 2009 by Matt Burns, a 30-year-old software engineer from Bristol, after two of his own cameras were stolen in a burglary at his home.

The principle behind the site is simple enough: every digital camera picture includes certain codes that associate it with the camera that took it. They can be erased, but it's difficult, and if you are simply uploading pictures to a site such as Flickr or Facebook, it's probably more trouble than it's worth.

Depending on the make, the details embedded in the photo – known as the EXIF data – include the camera's unique serial number.

Hayes, who lives in Melbourne, recalls: "Without any expectations whatsoever, I entered my missing [camera's] serial number. First hit. Bang. Straight to a Flickr account. A photo is shown, taken in March this year and uploaded shortly after. I check the EXIF data of the image and it's my camera, my serial number and my missing lens."

Hayes said he had "the most incredible feeling" when he realised he had rediscovered his lost gift.

It was indeed Hayes's camera – a Canon 5D MKII – that had been used since May 2009, just six weeks after it was stolen. The new user had even used it to take a photo of himself posing in front of a mirror, which he posted on Facebook.

Even better, a web search turned up the address of the person who had taken the photos (to show off their business) – and they happened to live just a short walk from a police station.

After a short investigation the camera and lens were returned to Hayes, who had been able to retrieve a copy of his original invoice.

For Burns, Hayes's story is the most prominent of what he hopes will be a string of success stories that will help reunite people with their treasured (and valuable) cameras. Other cases include a South African man who, after his camera was stolen, decided to sell its charger. He was then contacted by the person who bought that, having realised he had purchased the stolen camera.

Burns has been adding camera serial numbers embedded in pictures into his database since April 2010. Although not all cameras include them, Burns says "the newer, more popular cameras do write the information. Most DSLRs [professional-grade digital cameras] do."

Among the makes supported by his database are Canon, Casio, Kodak, Fuji, Hasselblad, Hewlett-Packard, Leica, Nikon, Olympus, Panasonic, Pentax, Phase One, Ricoh, Samsung, and Sigma. Smartphones aren't supported - yet: "In theory it would work with smartphones in the same way, however I've yet to find a model that writes any useful ID in the EXIF," Burns says. "I may find a way though, it's just not been an area I've focused on. I may for example find some models write the IMEI [unique handset number]."

Burns's site – much of which he produced while in Cambodia on a 12-month round-the-world trip – is growing fast, with more than 50,000 daily unique visitors in May alone. The database itself is growing quickly too: anyone can add an extension for the Google Chrome browser that will check any serial numbers found in photos online and pass them back to the database.

But couldn't whoever stole the camera just delete the EXIF data? "It's pretty trivial for a determined thief," admits Burns. "However, I think that having to do this makes a stolen camera much less valuable. Also, if the new owner didn't know it was stolen, they wouldn't wipe the EXIF data."

That's exactly what happened in Hayes's case. The person who ended up with the camera will not face charges, as the police have accepted that he had no part in the original theft.

Burns has also created a business model for his site: the first search is free, but anything more requires a paid login, which will search many more details from the EXIF data.