Sussex Police are warning cash machines users to be wary of a cunning scam which could cost them their card.

Thieves have been inserting a tiny clear plastic pocket into the card slots of cash machines.

When customers put their cards into the slot and attempt to enter their pin number, the machine repeatedly asks for the number because it is unable to read the strip on the card.

While the user keys in their card number several times, the thief watches over their shoulder and notes the number.

When the person tries to retrieve their card, the plastic pocket holds on to it so they have to leave the machine to report to their bank that the card has been withheld.

The thief then removes the plastic pocket with the card. He then puts the card back in, uses the pin number and withdraws cash.

Police are urging people to run a finger along the slot at cash dispensers before using them.

If a plastic pocket has been inserted, two prongs used by thieves to pull the pocket out can be felt.