Hundreds of thousands of online bankers are leaving themselves open to fraud, with £4.5m stolen from 2,000 people in the past nine months.

The number of victims of scams that steal online banking details soared in the nine months to June, up from 100 in 2003. The banking group Apacs, which acts for the clearing banks, said they were the hapless targets of "phishing" e-mails. These are crafted to appear as though they have come from a high street bank, and lead people to websites that mimic those of the bank.