More than 120 Britons have been tricked out of a total of £12.6m by so-called 419 scams in the past 15 months.

Police have recorded 97 incidents of people falling for advance-fee email scams in 2003, with a further 32 cases so far this year. The victims lost an average of £98,000 each.

Advance fee frauds, commonly known as 419 scams, usually involve a victim receiving an unsolicited email containing a promise of vast wealth.

Before the 'lucky' person can claim the untold millions, they have to pay an advance fee which, of course, they never see again. 419 refers to the section of the Nigerian penal code which such frauds breach.

"You have to wonder who's falling for these scams. It seems they're both rich and stupid," said a law enforcement source.

Police forces are warning that organised criminals use money generated from online scams to fund serious crimes, and that businesses are at risk.

"They rely on duping computer users, and it is quite possible that they could be users in your business. That means your business systems could be vulnerable," a source said.