The eraser at the end Telegraph picture

A gang had allegedly put up advertisements outside a south Calcutta branch of a bank offering “easy documentation” for loans and cheating customers by re-writing cheques for Rs 250 collected as documentation fee.

The gang allegedly used a pen with an eraser attached to it to tamper with the cheques, police said.

Arup Das, 33, of Garfa, Mithun Haldar, 24, of Jadavpur rail colony, and Surendranath Jaiswal, 42, of Garfa were arrested based on a complaint filed by a resident of Maipith in South 24-Parganas. Several cancelled cheques, bank forms, a mobile phone and the pen were seized from them.

Dinobondhu Halder, 32, had spotted the advertisements on a wall outside the Baghajatin branch of a nationalised bank and called on the phone number mentioned in them.

“The gang targeted people not well versed in paper work. They would ask clients to meet them with a cancelled cheque and a signed cheque. After helping the clients fill in some forms, the members of the gang would ask them to pay Rs 250 in cheque with the beneficiary’s name kept blank,” an officer at Lalbazar said.

The customers would be given the pen with the eraser to write the cheque. “The gang members would later erase the figure and use the same pen to fill in a figure of their choice,” the officer said.

In Halder’s case, a cheque for Rs 37,000 was allegedly written. When the money was debited from his account, Halder received an SMS alert. He then filed a police complaint.

Patuli police, during investigation, found CCTV footage at the bank that showed one of the suspects waiting for cheque clearance.

When the police tried to trace the phone number mentioned on the posters, it was found that the SIM card had been inserted in 11 mobile phones to throw the cops off track. The Patuli police laid a trap and contacted the racketeers posing as clients, leading to the arrests.