Salt Lake: The man arrested in the airport on Tuesday in connection with a money laundering case apparently misused voter identity and PAN cards of people to open bank accounts.

Hanish Toshniwal, 28, knew several businessmen in Baguiati, Rajarhat and New Town, police said.

All these areas see plenty of cash transactions because of the real estate boom, an officer of Salt Lake cyber crime police station said.

Toshniwal, who lives in Baguiati, was arrested after he landed in the city from Delhi.

Cops are going through his call detail record to find his contacts, an officer of the Bidhannagar commissionerate said. "We are trying to find out why he went to Delhi and whom he met there."

A group of Karnataka Bank officials and others had created 70 fake accounts in the Rajarhat branch to channel more than Rs 100 crore into them from various sources after the demonetisation.

Toshniwal acted as the middleman between bank officials and those who wanted to deposit unaccounted for money, the police have said.

The matter came to light when Santosh Sharma of Lake Town's Dakshindari lodged a complaint with the police station in February. In his complaint, he referred to an income tax letter asking him about Rs 7.6 lakh deposited in his current account at the bank's Rajarhat branch.

The police had arrested Madhusudan Grandhi, the manager of the bank's Palm Beach Road branch, Navi Mumbai, in Calcutta on July 13. Grandhi had been posted at the Rajarhat branch when the accounts were opened. He was released on bail five days before Toshniwal's arrest.