A new kind of telephone scam is taking advantage of people's awareness of credit card fraud, police warn.

Ottawa police Sgt. Mike McCormick said fraudsters are now calling customers claiming to be from the fraud department of their credit card company.

"We know as a general public that there's a lot of fraudulent activity on credit cards and debit cards, so when we start hearing … your financial institution calling you ask you for specific information and providing information that nobody else should know, it brings down our wariness," said McCormick, who is with the organized fraud section.

He said investigators are seeing a steep increase in reports of a scam in which a caller names an unusual big-ticket item and asks if the customer has recently purchased it.

When the customer says no, the caller says the company involved has been cropping up in a lot of suspicious transactions.

The caller provides a reference number for the customer's file and give the customer a 1-800 number to call.

He or she also asks the customer to confirm that they still have the card by providing the three-digit security code marked on the back.

Fraud investigators say no legitimate credit card company will ask you for that code.

McCormick said the fraudster typically already has your address and credit card number, usually from dumpster diving for receipts and bills.

RCMP Corp. Louis Robertson, head of criminal intelligence at Phonebusters, a joint RCMP-OPP unit aimed at phone fraud, said customers can take measures to protect themselves.

"If you go to any store, you can buy a shredding machine for $20 to $25," Robertson said. "I think it would be a great, great investment."