Zurich -- Counterfeiters who already earn money from fake Swiss watches and army knives have now turned to making a business out of fake Swiss rubbish bags.

Police in the Swiss canton of Zurich said Thursday that they have uncovered thousands of counterfeit rubbish bags carrying the region's waste disposal tax and recycling label, smuggled in from Serbia.

Each 35 litre so-called "Zueri-sack" is sold at about CHF 2 (EUR 1.3, USD 1.8) as it includes a tax levied by the cantonal waste disposal and recycling authorities.

Waste disposal services in the canton only collect the pre-taxed bags.

"A 37-year-old man has over several months smuggled thousands of fake rubbish bags from Serbia to Switzerland where they are sold," said Zurich police in a statement, noting that the value of the offence reached CHF 26,000.

Cartons of trash bags were first discovered during border control checks on a tour bus coming from Serbia.

A Serbian man was found to have the fake bags at his grocery store in Zurich.

Police said experts found the fakes were "relatively good" but that the bag tears more easily compared to the Swiss originals.

The main difference between the two was the colour, said police, noting that the counterfeits carried a darker blue than the original "Zueri-blue."

Police appealed for people who may have the fakes to return them to the authorities, who will "replace them for free so that the rubbish can be correctly disposed of."

AFP / Expatica