People taught a cop-turned-extortionist a lesson on Monday after catching him extorting money from hawkers.

Lake Gardens residents forced Dibyendu Shekhar Rez, attached to Lake police station, to return the money to the hawkers and let him go only after senior officers intervened.

“We warned the officers that Rez would not be released the next time he was caught hounding people,” said a resident.

Witnesses said Rez arrived in front of Dhaka Kalibari, in Lake Gardens, around 9.30am, riding his motorcycle.

“He parked his two-wheeler and started extorting money from the hawkers. Rez fixed the amount — ranging from Rs 50 to Rs 75 — depending on the volume of wares of each hawker,” said Amit Roy, a witness.

The hafta routine took an unexpected turn when one of the hawkers called up Indranil Saraswati, the secretary of DYFI’s local unit, and informed him about the rogue cop.

“I rushed to the spot and was stunned to see the officer in uniform collecting money. When I asked him why he was not issuing receipts, Rez said the hawkers will have to collect receipts from the police station. He was trying to cover up after being caught redhanded,” said Saraswati.

The goon in uniform argued that he was taking valid action against hawkers for encroaching on the pavement. But he “failed to give a satisfactory answer” when residents — many had surrounded the officer by then — asked why civic officials were not accompanying him.

“We asked him whether he was acting on orders from his superiors. Then, he confessed that his bosses were not aware of his extortion drive,” said Saraswati.

“We then ordered him to return the money to the hawkers and called Lake police station. He was released only after his senior colleagues assured us that Rez would not be seen harassing people again,” said Ashish Deb, in the group that gheraoed the greedy sergeant.

Rajesh Subarna, the deputy commissioner of police (south), later said: “An inquiry has been ordered against Rez. Action will be taken against him if he is found guilty.”

Subarna appealed to the residents to lodge a complaint against Rez.

This is not the first time that Rez has been at the receiving end of people’s fury. Sources said a woman had slapped the sergeant in Rabindra Sarobar a week ago for “misbehaving” with her. Not long ago, students of South City College had attacked him over his alleged misconduct.