credit card holders are being warned by police after several people fell victim to a phone scam.

Police say that on no account should anyone give out their seven digit security number on the back of their card to anyone.

As part of the fraud, people have been conned into giving out the security number, which allows other people to use their card.

The cardholders had been contacted by someone claiming to be from a security and fraud department at a credit card firm, saying they were checking out suspect purchases which had appeared on the account.

The person on the phone even read out the victim's address and card number.

In order to verify that it had not been stolen, the fraudster then asked for the seven digital security number on the back of the card.

Cardholders have later found that purchases had been charged to their accounts.

Sgt Ian Coop, of Bolton Police, said: "The message is don't give out your security number or even your pin number to anyone you don't know.

"Banks and credit card companies will never ask for such details and if there are any specific problems with your account, they normally write to the cardholder.

"I would be very suspicious of anyone who contacts you by phone.

"If in doubt, take the persons details and contact the bank or credit card company in person to establish if the caller is legitimate."