UK credit card and debit card fraud on the internet is much greater than previous estimates, findings published today have suggested.
Bank industry figures published earlier this year show "card not present" losses for internet, phone and mail order crime were £290.5m last year.
But a BBC News investigation found that £500m of fraud took place when failed attempts were taken into account.
Posing as computer hackers, two BBC News journalists infiltrated a website selling thousands of card details which had been stolen online from small internet retailers.
When the cards were used, they traced the fraudulent transactions to a number of addresses in the UK and confronted people who signed for the goods they had bought.
The information is being passed to the police, the BBC said.
Figures from the Association for Payment Clearing Services (Apacs) showed a 25-per-cent increase in overall card fraud to £535.2 million last year.
Of this, £290.5m was "card not present" fraud by phone, internet or mail order, a rise of 37 per cent on the year before.
The rise in overall card fraud is being mainly driven by criminals working overseas using stolen UK card details, it said.
Earlier this month a report by web security company Symantec revealed that bank account details were selling for as little as £5 as part of a thriving trade in stolen information on the internet.