A fraud prevention expert has argued that the danger to consumers from last week's TK Maxx data theft has been over hyped.

Paul Simms, chief executive at security company The 3rd Man, said: "If it is true that 45 million customers have had their cards compromised, that is obviously very serious.

"But fraudsters often obtain card numbers from a variety of sources. Provided security information has not been compromised then there is no need for wholesale panic."

According to reports, customers of TK Maxx have already had card details used in fraudulent circumstances.

"Card numbers on their own pose little threat," said Simms. "Card numbers together with names and addresses or security numbers would represent a problem, but I would be highly surprised if this were the case."

Simms added that it should not come as a surprise that card crime continues to flourish.

"We saw it with chip and Pin and the move to 'card not present' crime, such as over the internet and mail order," he said. "Since then many retailers have put in place systems to prevent 'card not present' fraud."

A card number without a Pin is of little use in shops, and a card number without the security number will be of little use on the internet or over the phone, the security expert argued.

"This story must not scare customers from shopping online," said Simms.