Two suspects have been arrested and charged with conspiracy to defraud.

The DCPCU says early indications suggest these criminals have been tampering with retailers' chip and PIN terminals in order to steal card transaction data and PINs.

Equipment needed to steal card details and make counterfeit cards on a massive scale was found on the premises, including stolen chip and PIN terminals, card account numbers, a card reader and writer, computer software and fake magnetic stripe cards.

With these details, criminals are able to create fake magnetic stripe cards that can be used fraudulently in countries that have yet to roll out chip and PIN. This type of fraud - committed on UK cards abroad - increased 77% last year, totalling £207.6 million, according figures from Apacs.

An Apacs spokesperson told Finextra that the devices recovered from the police raid have been sent for forensic examination.

Detective Chief Inspector John Folan, who heads up the DCPCU, says the arrests are a significant development in the fight against the organised criminal gangs responsible for card fraud.

However Folan also says that to date, "compromised chip and PIN terminals" have been found in around 30 retail outlets across the UK.

Sandra Quinn, director of corporate communications at Apacs, maintains that chip and PIN is "the safest method of payment".

"In the unlikely event a cardholder is an innocent victim of this or any type of fraud, they enjoy excellent protection under The Banking Code, which means that they will not suffer any financial loss," says Quinn.