Safe sex may not be quite so safe in China. Police have uncovered underground workshops churning out fake condoms in the latest expose of China’s counterfeit industry.

The spread of knock-off prophylactics is rampant, state media said. Users can expect little or no protection even though the condoms in question carry the most famous brand names.

The scandal surfaced when police raided a workshop in central Hunan province that was producing counterfeit condoms. The police warned that the contraceptives had already been distributed nationwide and many people may have already bought and used the poor quality items, risking both pregnancy and disease.

Police are still looking for as many as a million condoms produced by the illegal factory.

Four people have been arrested in that condom bust and police described the operation as well organised in the 20-square-metre workshop.

Bare-chested employees were found using vegetable oil to lubricate the condoms to make them smooth and shiny before placing them directly in fibre bags without bothering with sterilisation.

Since March, the workshop had turned out 2.16 million unsterilised condoms labelled as “Jissbon”, “Durex”, “Rough Rider”, “Six Sense” and “Love Card”. The workshop had earned about 80,000 yuan (£7,000).

One police officer said: “This is by far the largest case involving producing and selling fake condoms in Hunan Province."

He warned buyers that price was a good clue to a counterfeit condom. One online shop based in Hunan province was offering Durex and Six Sense condoms at 15 yuan (£1.30) per pack of 12. The normal market price for Durex condoms in supermarkets and pharmacies is 49 yuan a pack.

The owner defended his products, before hanging up the telephone. “All my products are genuine and sourced from the authorised agencies of the manufacturers.”

The temptation is high to turn out fakes in China — whether DVDs, Louis Vuitton handbags or BMW cars — due to the low cost of labour and raw materials and the difficulty for the police in tracking down such enormous and spread-out workshops.

Officials estimate that a third of all condoms in some areas are fake. The condom market in China is the fourth-largest in the world with annual sales of about two billion. The market is important in a country with a strict family planning policy that restricts urban families to one child per couple.

Times Recommends

• New York has lost its edge
• Copenhagen will fail – and quite right too
• More than 17,000 new underwater species found