The CBI investigation into surprise credits totalling Rs 820 crore in the accounts of UCO Bank customers has brought under the agency's scanner thousands of recipient accounts which were opened around the dates the transfers took place, PTI quoted officials as saying.

The CBI is probing a case where over 41,000 UCO Bank customers received surprise credits of varied amounts in their accounts during November 10-13 without any corresponding debits in the originating accounts, they said.

Among various leads, the agency's needle of suspicion has also gone on "thousands of accounts" which were opened around the time the transactions started and received the transfers, the officials told PTI.

The Central Bureau of Investigation (CBI) had earlier said in a statement that several account holders allegedly exploited this situation, illicitly withdrawing funds from UCO Bank through various banking channels, thereby benefiting wrongfully from the transaction.

"No one who received the funds without criminal intent needs to worry about our investigation. We focus only on those who conspired and orchestrated the massive scheme. It is an early stage of investigation, and all angles are being looked into," an official said.

He added that people must beware of fraudsters who may want to exploit the situation by posing as investigators. The CBI does not make phone calls to get details in the case, hence, he said in cases of such calls, people may approach the agency directly.

The agency has noted that Rajasthan was the most affected state in the money transfer case, recording 7.50 lakh transactions in three days spread across 230 branches and 28,000 accounts in which Rs 760 crore were transferred.

This was followed by Karnataka and West Bengal, where Rs 3.40 crore and Rs 2.60 crore were transferred, PTI reported quoting officials.

The officials said the money landed in accounts of UCO Bank customers through 8.53 lakh Immediate Payment Service (IMPS) transactions originating from 14,000 account holders of private banks in three days.

Surprisingly, they said no corresponding amount was debited from the originating bank accounts. Several account holders withdrew the surprise credits from their accounts, the officials said.

The countrywide transactions resulted in a CBI FIR after UCO Bank approached the central agency with a complaint against two support engineers working with it and other unknown persons on allegations of "suspicious" IMPS transactions amounting to approximately Rs 820 crore, they said.

"During the searches, electronic evidence, including mobile phones, laptops, computer systems, email archives, and debit or credit cards were recovered," PTI quoted a CBI spokesperson as saying earlier.

He had said that between November 10 and November 13, IMPS inward transactions from 14,000 account holders across seven private banks were directed to 41,000 UCO Bank account holders.

"It was further alleged that this intricate network involved a staggering 8,53,049 transactions, and these transactions were mistakenly posted in UCO Bank account-holders records, despite the originating banks registering failed transactions," the spokesperson had said.