This new way of reducing the increasingly common copper thefts is currently being tried out by the Swedish Transport Administration (Trafikverket) and has seen previous success, reported newspaper Dagens Nyheter (DN).

“We’re going to try this method which has been very successful in other countries. It has also been tried out in stores in Stockholm with good results,” Sten Vickberg, head of security and maintenance at the Transport Administration told DN.

A substance is smeared onto the rails, marked with traceable ID materials, which make finding the copper possible.

The markings can only be found by light of a UV lamp, which all Swedish police are now being equipped with, reported DN.

The Transport Administration is also considering replacing the copper so hotly desired by robbers with aluminium.

Problems with copper thefts have long plagued the Swedish railway, with costs of up to 120 million kronor ($16.5 million) every year just for material losses. Even more expensive for society are the huge delays caused by the copper thefts.

The railway isn’t alone in being struck by copper thieves. Many Swedish churches have also been stripped of their venerable copper details, or even their entire copper roof.