LONDON (AP) — Three bandits were foiled in Britain when their attempt to pry open a stolen cash box ran up against a new security system that slathered the bills with glue.

Baffour Amponsah, 25, Brian Ocaya, 28, and Daniel Collins, also 28, were part of a gang that ambushed a cash delivery man working for security company G4S in south London on Jan. 16, 2011. The group stole his cash box but ran into trouble when they retreated to a parking lot to try to open it.

Gavin Windsor, a G4S director, said the company’s cash boxes had recently been fitted with a new security system which coats the bills with glue — along with dye and a colorless, traceable liquid known as “smart water” — if it is tampered with.

“We now have a system within that box that guarantees that when it’s activated, the glue and the dye and the smart water activates within the box and gives you complete coverage,” Windsor said in a telephone interview. “For all intents and purposes it makes (the money) unusable.”

Police said in a statement Wednesday the gang was spotted by a witness less than an hour after the robbery as they struggled with the glued-up bills. Plainclothes officers swooped in and arrested Amponsah and Ocaya at the scene; Collins was arrested several months later.

Amponsah pleaded guilty and received four years and two months in jail. Collins and Ocaya were sentenced to six years and six years and 10 months, respectively.

Although dye bombs and traceable solutions have long been used by security companies and law enforcement as a deterrent against cash robberies, Windsor said that using glue to gum up bills was a relatively new innovation, one he says his company and others have been working on.