Conmen are cashing in on the bank charges controversy by cold calling customers and offering to reclaim bank charges on their behalf. The Office of Fair Trading, which today issued a warning about the scam, said that the telephone callers were impersonating OFT officials and asking bank customers for current account details.

The OFT said: "These callers have no connection with the OFT, and their intention is to use the information for identity theft or to run up bills or commit crimes using stolen details. The OFT will never contact consumers asking them for personal bank details."

The scam is a new version of 'phishing', were conmen send emails to bank customers asking them to divulge their account details so the 'bank' can update their files. Banks and building societies say they will never email customers asking for personal account information.

Mark Dungworth, a case manager in the OFT’s ScamBusters department, said in cases like this fraudsters who obtained people’s account details tended to act very quickly and could take thousands of pounds out of people’s accounts in a very short time.He said: “These people are opportunistic and they will use anything they can find in the news to try to make their story more plausible.”

He added that fraudsters often told people things they wanted to believe, such as pretending they would be refunded bank charges, in order to get them to part with their details.

Tens of thousands of current account customers have already reclaimed billions of pounds in overdraft charges from banks. Some banks charge penalty fees of up to £30 for those who slip into the red without permission.

New figures show that current account holders have paid out an average of £742 in 'illlegal' penalty charges over the last six years. But several major banks, in association with the Office of Fair Trading, have launched a test case in the high court to establish the legality of the charges. Until this case is decided early next year, all bank charge claims have been frozen.

Those worried about the new scam can call Consumer Direct on 08454 04 05 06 or visit the scams area on the OFT website : www.oft.gov.uk.