The law enforces, however, failed to arrest anyone in this connection.

The law enforcers found hundreds of drums of used and counterfeit engine oil inside the factory, police sources said.

Sources said the owner of Sithi International Abul Kashem used to mix colour and chemicals with used lubricants to make it look like fresh engine oil.

Kashem, manager of the factory Mukhlesur Rahman, and other workers had fled the area before the law enforcers reached the factory.

A security guard of the factory said the factory used to produce around 2,000 litres of counterfeit engine oil every day for distribution throughout the country during the night.

Locals claimed they had complained about the factory several times to the police but no action was taken.

However, Rafiqul Islam, office-in-charge of Devpur Police Station, said he had been transferred to the police station recently and he was unaware of such complaints against the factory.