A man who allegedly stole about 1.28 million yuan (US$200,000) worth of electricity equipment 10 years ago has been finally nailed — because of a cigarette butt, and a problem at his restaurant — Shanghai police said on Wednesday.

The suspect, surnamed Meng, was caught after Huangpu District police decided to take a fresh look at the decade-old "cold-case" and found a link with an administrative offense four years ago involving the illegal use of equipment in a restaurant in the same area.

The theft took place on a late autumn day in 2008 at an electricity distribution substation on a street next to the Huangpu River and was reported to police by an employee of the electricity company surnamed Liu.

Over 20 pieces of electrical engineering equipment and two transformers were stolen.

There were hardly any clues because the electricity station was not equipped with surveillance cameras and there were no residents nearby.

But police found a cigarette butt that had probably been dropped around the time of the burglary.

Since smoking was banned inside the substation and Liu was a non-smoker, police suspected it could belong to the thief. And it it did.

This year, in their renewed effort to solve the case, police using new forensic technologies matched the butt with biological information on file for a man who illegally used a piece of equipment four years ago in a restaurant he runs in the subdistrict where the theft occurred.

Meng, who runs the restaurant, confessed to to 10-year-old theft, police said.