The four men fixed the chip and PIN devices in various petrol stations last year in order to copy the electronic data from customers' credit and debit cards.

They then used this information to make fake magnetic stripe cards that could be used fraudulently overseas in countries yet to introduce chip and PIN. According to the BBC, the nine-month fraud caused losses totalling £725,000.

The gang's mastermind, Theogenes de Montford, was sentenced to four-and-a-half years' imprisonment at at Southwark Crown Court after pleading guilty to conspiracy to defraud and conspiring to possess articles for use in fraud. When he was arrested, police found details for 35,000 cards on his laptop.

Rajakumar Thevathasan, Usman Mahmood and Rashid Abdi Hassan each received three-and-a-half years after being found guilty of conspiracy to defraud.

Detective Chief Inspector John Osibote, DCPCU, says: "This is another resounding success for the DCPCU. As a result of this operation, the Unit has prevented a significant amount of card fraud from taking place. We have worked closely with both the banking and retail sector on this investigation, and together we are sending a very clear message that those responsible for these types of fraud will be caught and prosecuted."