Fraudsters are moving with the times, with many now using e-mail to cheat innocent web surfers of their hard-earned cash, according to a new study.

Ninety-four percent of respondents to a National Consumers League survey said they had received unsolicited emails offering financial services or touting dubious money-making schemes.

The NCL, the main US consumer lobby, warned that many of these offers could be fraudulent.

"Consumers should be very suspicious of anyone who promises them easy money, incredibly cheap prices, or 'free' services that may have hidden costs," said Susan Grant, director of the NCL's Internet Fraud Watch programme.

Beware the inbox

The fastest-growing internet fraud is an online version of the notorious 'Nigerian money offer'.

Reports of e-mailed Nigerian money scams - designed to obtain recipients' bank account details by offering to transfer large sums to them for safekeeping - rose by 900% between 2000 and 2001, the NCL said.

Scams of this kind, which often emanate from Nigeria or other African countries, have been circulating for years through the post or by fax.

Other frequent internet scams include bogus auctions, dubious work-at-home schemes, and phoney credit card offers.

Hall of shame

The top 10 internet frauds reported to the NCL last year were:

• Bogus online auctions, where the items purchased are never delivered.
• Deliberate misrepresentation or non-delivery of general merchandise purchased online.
• Nigerian money offers.
• Deliberate misrepresentation or non-delivery of computer equipment or software purchased online.
• Internet access scams, where bogus internet service providers fraudulently charge for services that were never ordered or received.
• Credit card or telephone charges for services that were never ordered or misrepresented as free. These often include charges for accessing 'adult' material.
• Work-at-home schemes promising wildly exaggerated sales and profits.
• Advance fee loans, where consumers are duped into paying upfront charges for loans which never materialise.
• Phoney offers of cheap-rate credit card deals, once again on payment of upfront fees.
• Business opportunities or franchises sold on the basis of exaggerated profit estimates.

Law enforcement agencies have long warned that the rise of the internet has opened up fresh opportunities for fraudsters.

Last year, the European Commission said that online shopping sites had contributed to a 50% rise in credit card fraud in the European Union during 2000.