Scotland on Sunday reports that up to half a billion pounds in cash stolen from credit card and bank accounts every year goes unreported because banks have a policy of reporting only thefts of Â£2,000 or more to police or outside authorities.
An estimated one billion pounds disappears from accounts annually as a direct result of cyber-crime, with around half written off by institutions, according to banking security experts.
A banking industry insider told Scotland on Sunday: "We would only report something under Â£2,000 if it were clear that it was a part of a much larger fraud. It may seem a lot to you, but for the bank it costs more in the time taken up by speaking to police and lawyers."
The newspaper raises concerns that internet criminals may be encouraged to steal more from bank and credit card customers because so little fraud is reported and claims that MPs and MSPs are demanding an investigation into the true extent of online financial fraud in Britain.
Organised gangs of criminals from Eastern Europe are believed to be targeting customers using new radio devices that can pick up on signals from chip and pin card readers and bribing or threatening bank and call centre staff to gain information on accounts.