A schoolteacher was coaxed into sharing her and her daughter’s banking details with a person who identified himself on the phone as an official of a nationalised bank’s Triangular Park branch where she has a savings account.

The person called on Thursday and apparently said her account would be closed as her KYC documents weren’t updated and that the only way to prevent it before the total lockdown and the weekend was to share with him her debit card details.

Once he got hold of the details, he carried out multiple online transactions and told her that he was transferring the money from her account to the bank’s e-wallet service, police said.

After transferring close to Rs 40,000, the caller asked for the card details of other family members, complainant Debjani Biswas, 47, said.

The resident of Panditiya Road in Ballygunge said the first call came on Thursday morning before the government called off the total lockdown on Saturday. “The caller knew I have an account in the Triangular Park branch; so I did not doubt him. He kept saying my account would be closed and that I would have to pay a penalty of Rs 4,000 as my KYC documents were invalid,” Biswas, who teaches in a Ballygunge school, said.

“He said there was no way to update the documents in the next three days because of the two-day total lockdown and Sunday. He told me that he would do the needful if I shared my card details with him.”

She told Metro on Saturday that every time the person made an online transaction, she received an OTP on her phone. She had shared the OTPs with the caller in good faith, thinking the money was being transferred to an e-wallet of her own account, she said.

When she refused to share card details of other family members, the caller apparently told her that the entire money would be withdrawn from her account. When she still hesitated, the caller hung up only to call again the next morning.

“This time, I was standing right near my mother when the call came. He kept insisting we would lose a lot of money if we did not add a nominee to my mother’s account and that he needed my card details to do that,” Biswas’s daughter Tiyasha, 20, said.

“My mother had panicked… just to console her, I gave her my card from another bank. But before I could react she had shared my card details, along with the CVV (a 3-digit number printed on the signature panel on the back of the card). The person tried to carry out online transactions from my account, too. But luckily there was little money and the transactions were possibly declined.”

The man spoke in Bengali and had full knowledge of Biswas’s account number. Realising the fraud, she and her daughter lodged a complaint with Rabindra Sarobar police station and then with the anti-bank fraud section at Lalbazar.

Preliminary investigations showed the money had not been transferred to any e-wallet. It had been used for purchases on various online portals, the police said.

Hundreds of people are cheated similarly on the phone every month. In June and July, the city police had received more than 1,700 such complaints, of which close to 1,600 had a connection with Jamtara in Jharkhand.

In the case of Biswas, cops are still to ascertain where the call came from, the police said.