Further details have emerged of the Diss card cloning scam, with one building society outlining how the events unfolded and urging customers to be vigilant.

Further details have emerged of the Diss card cloning scam, with one building society outlining how the events unfolded and urging customers to be vigilant.

The Norwich and Peter-borough Building Society revealed on Thursday that it had stopped 155 of its customers' cards after being notified of suspicious transactions which were traced to the Shell petrol station in Victoria Road.

A spokesman for the building society said 29 customers, whose cards had been copied, had £21,000 withdrawn fraudulently from their accounts in countries including Canada, Malaysia and Thailand.

Both the Norwich and Peterborough and Barclays have said they will reimburse customers who have lost money as a result.

A 30-year-old man has been arrested by Norfolk police on suspicion of conspiracy to defraud in connection with the complaints and has been released on police bail pending further inquiries.

Last night, Andrew Clare, head of banking at the Norwich and Peterborough, said the chain of events was sparked on Sunday when some customers notified Transaction Network Services (TNS), the global communications company that enables payments, money or voices to move around the world, that their cards had been the subject of suspicious transactions.

The building society launched an investigation on Monday morning after being alerted by TNS. Later that day, the building society began contacting customers and cancelling cards.

Mr Clare said there were several ways that cards could be cloned, one of which could involve tampering with the card reading device to enable it to copy the information in the black magnetic stripe.

“The reason that cards are being copied and used abroad is because some countries have not yet introduced the chip and pin technology that we have in the UK,” he said. “It's the magnetic stripe on the back of the card that is being copied and used.”

Mr Clare described the Diss card cloning scam as a “significant” incident.

He said one customer had lost £95 while others had lost more than £1,000.

Mr Clare advised: “The best way to avoid your card being copied is to never let anyone take it out of your sight, even to use a machine under a counter. If the retailer says he must take your card to a machine, you should go with him or suggest that you go and get cash from an ATM.”

Shell has said the security of its customers is its “primary concern” and it was helping the police with their investig-ation. It has also launched its own investigation.

SECURITY ADVICE

1-Guard your card and card details.

2-Don't let your card out of your sight when making a transaction.

3-Ask the retailer to confirm the amount being debited on your card.

4-Carefully discard receipts from card transactions.

5-Check your receipts against transactions and keep a check on your bank balance on a regular basis.

6-Never write down your pin number, and never disclose it to anyone who claims to be your bank.

7-Be wary of people watching you while you enter your pin number.

8-Report lost cards or suspended fraudulent use to your bank straight away.

9-Report any suspicious behaviour to the police straight away.