A group of men allegedly accessed a shopping portal’s customer list illegally, posed as Flipkart officials and lured a few customers to transfer money into several accounts as participation fee for a fictitious lucky draw contest with false promises of assured gifts.

Three people have been arrested in connection with the case and charged with forgery, cheating, fraud and impersonation.

Senior officials of the Flipkart Internet Pvt Ltd lodged a complaint with Hare Street police station in March after which the case was handed over to the anti-fraud section of the detective department.

“The accused persons had made calls or sent phishing mails to the customers inviting them to participate in a lucky draw scheme that had assured return gifts. Several people had fallen into the trap and transferred money into the accounts as mentioned by the imposters. But later, the fraud was realised when the customers neither got any gifts nor was the money refunded,” said a senior officer of the detective department.

Police investigation had revealed that the fraud had started in December 2018 and was detected a few months later. Investigators suspect that someone with access to customer data had leaked it to the fraudsters.

Although initially it was found that the documents with which the bank accounts had been opened were false, cops managed to zero in on the accused through their phone numbers. Investigators have started tracking the details of the bank accounts where the money was transferred.

Based on specific information, two youths men — Gulraj Ahmed, 23, and Vishal Sharma, 25 — were arrested from in front of the GPO on NS Road on Friday afternoon.

Pursuing their statement, a third accused, Mohammad Sadik, 20, was arrested from near Chingrighata crossing along the EM Bypass later on Friday.

Officers examining the trio found that the team used to operate from a house in Prafulla Kanan area in Baguiati.

“False identity documents used for opening bank accounts, customer database of the Flipkart, CPU and hard disks were seized from the Bahuiati address,” said a cop.

A local court has remanded all the three accused in police custody on Saturday.

Lakhs of people who opt for online transactions are at the risk of their data being stolen or misused by people who handle them.

Asked, Flipkart declined to comment. However, a source close to the e-retailer denied any leak of sensitive information from the customer database. “It is an offline breach,” said the source.

The source said: “It is possible that these people followed the delivery boys and acquired knowledge about the customers buying pattern, which aided them to trick unsuspecting buyers with offers of goodies.”

“All reputable portals have their security features that protect the privacy of their customers. But it becomes difficult to protect data is someone from inside breaches the system. In this case, it is yet to be ascertained, how the data got leaked,” an officer who is part of the probing team, said.

The police have seized several documents containing a list of Flipkart customers.

A police officer said shopping portals had their own customer safety manuals and usually do not call their customers.

“It is advisable that people should not make online payments to any unknown accounts unless it is through the official website or the app of the portal,” the officer added.