Delhi police has arrested a 32-year-old man who allegedly had been running one of the biggest online credit card frauds in the country.

Raju Tevar, a resident of Mumbai, stole data of customers if a private bank and made illegal transactions totaling cores of rupees.

Investigators said that Tewar posted as an ICICI bank executive and obtained the victims' details on the pretext of preventing a sham transaction from their accounts. Then he used the details to make transactions from the victim's accounts to pay people's power bills, in return for which he collected huge piles of cash.

Tevar reportedly removed more than Rs 2 crore from bank accounts of nearly 4,500 ICICI customers over the past one and a half years. However, investigators are of the view that the magnitude of the credit card scam could be much bigger as they found details of as many as 30,000 customers in Tevar's laptop.

An officer involved in the investigation said, "They are just wondering how this happened for more than a year. We feel that a bank employee must be involved."

Raju is a school dropout who had worked as a rickshaw-puller, labourer and even as a domestic help. He told investigators that he stole the data from the laptop of his last employer, Zakir. He also revealed that Zakir had obtained the data from his girlfriend, who worked in the private-sector bank.

Police have so far failed to trace Zakir and his girlfriend as investigators are probing their involvement in the credit card fraud.