A gang making counterfeit washing powder that was being sold to the public as a popular brand has been smashed by gardai on the outskirts of Dublin.

A secret factory making the counterfeit Persil washing powder, at an industrial premises at the Greenogue Business Park in Rathcoole, was raided.

Three men were arrested in the long-running investigation.

The probe into the fake laundry product is understood to have been initiated after a complaint by Unilever, the makers of the authentic Persil range.

A source said the company had purchased and analysed a number of products that were on sale outside the traditional groups or retailers as Persil under a suspicion that they were fake.

After testing confirmed its suspicions, Unilever is said to have made a complaint to gardai who set up an investigation.

Following a surveillance operation, the premises in Rathcoole was raided at noon yesterday and goods to the value of €40,000 were seized.

A statement issued by gardai said the operation was part of the ongoing investigation into organised crime and the sale and supply of counterfeit laundry products.

The three men, aged from their mid-30s to late 50s, were brought to Clondalkin and Ballyfermot garda stations and detained under Section 4 of the Criminal Justice Act.

All three men were later released without charge. A file is being prepared for the Director of Public Prosecutions.