Most cases of counterfeit fraud involve skimming, where the genuine data on a card's magnetic strip is electronically copied on to another card without the legitimate cardholder's knowledge.

Skimming can occur at retail outlets such as petrol stations if a card is put through a copying device.

In some cases, hidden pinhole cameras have been used to record the PIN entered by customers.

The information is then sold on higher up the criminal ladder where counterfeit cards are made.

Criminals can then go shopping with copied credit or debit cards.

Cardholders are usually unaware of any fraud until their statement arrives, showing purchases they didn't make.

Some skimming takes place at cash machines where a skimming device has been illegally fitted.

Advice for cardholders: The Association for Payment Clearing Services, a banking trade association, issues the following advice to protect cardholders from fraud: n Guard your card and card details.

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

n Ask the retailer to confirm the amount being debited.

n Carefully discard your receipts.

n Check your statements carefully.

n Never write down your PIN or disclose it to anyone.

When using a cash machine, be wary of anyone who might be trying to watch you enter your PIN and do not allow yourself to be distracted.

If you are a victim of card fraud: Inform your bank or building society immediately.

If someone else uses your card before you tell your bank it has been lost or stolen, or that someone else knows your PIN, the most you will have to pay is £50.

Banks will usually refund the full amount lost unless you are shown to have acted fraudulently or without reasonable care.