The Special Task Force of Uttar Pradesh Police arrested 23 people and sealed seven petrol pumps in Lucknow for allegedly duping consumers, ANI reported on Friday night. The dispensing machines at these petrol pumps were allegedly fitted with a remote-controlled electronic chip to deliver less fuel to customers.

The police had sealed the petrol pumps on Thursday after they recovered 15 electronic chips and 29 remote controls. Of those arrested on Friday, four are owners, nine managers, nine salesmen and one technician, reported The Times of India.

Additional Superintendent of Police (STF) Arvind Chaturvedi said they had received a tip-off about an electrician in Lucknow who had developed this chip and sold it to pumps for Rs 3,000. Ravinder admitted that he has had sold this chip to more than 1,000 pump owners across Uttar Pradesh. “After being installed in the dispensing machine, it would reduce the output by nearly 6%,” Chaturvedi told The Times of India.

Senior Superintendent of Police (STF) Amit Pathak said these pump owners were earning a lot of “illegal” profit, reported The Indian Express. He pegged the figure at Rs 6 lakh per month for petrol pumps doing average sales and Rs 12 lakh per month for those doing good business.

The fraud has been going on for almost eight years now. Pathak said the chips were manufactured in Kanpur before being brought to Delhi to be attached with a remote and then installed in dispensing units across the state. Following this inspection, Director General of Police Sulkhan Singh ordered the formation of a special investigation team to check the menace.

Union Petroleum Minister Dharmendra Pradhan congratulated the STF team for busting the racket. “Petroleum ministry and OMCs will take strict action against those found guilty of short delivery and tampering with the dispensing units,” he said in Twitter.