Three men who had allegedly duped the driver of a private car and stolen a bag, containing cash and a diamond necklace worth Rs 4 lakh, from the front seat have been arrested.

Police said the gang would stop a car and raise a false alarm that fuel was leaking from the vehicle. As the driver would step out to check, the gang members would swiftly steal the belongings from the dashboard or the front seat — whichever was accessible.

On the afternoon of December 24, the driver of the complainant was allegedly tricked in a similar way on Jadunath Dey Road in central Calcutta.

“The complainant told officers of Bowbazar police station that the driver, on being told about the purported fuel leak, stepped out of the car to check. By the time the driver had returned to his seat, the gang had stolen a leather bag that was lying on the front seat and fled,” said an officer of the detective department, which has taken over the case from Bowbazar police station.

Once the theft was reported to Bowbazar police station, footage of CCTV cameras installed at the spot was analysed. The identity of the three accused was established based on the footage and source information.

“A watch was mounted on the suspects for a few days before they were nabbed by the cops from a location in Kalighat. Following their interrogation, the cops recovered the bag containing the diamond necklace worth around Rs 4 lakh,” said the officer.

The accused were identified as Akash, 24, and Sahil, 18, residents of Ambedkar Nagar in South Delhi and Mariappa, 35, from Indrapuri in North Delhi. They have been operating in various cities across the country, the police said.

“The accused used to come to Calcutta on and off to dupe people. In Calcutta they stayed in Kalighat. We have learnt they have duped several people in the city over the past few months,” the officer said.

The three have been charged under the Indian Penal Code sections related to cheating and criminal conspiracy.