A US man has been fined almost £48,000 for marketing a bogus anti-spyware program.

Zhijian Chen of Oregon made thousands of dollars by sending spam messages that fooled people into believing that their computers were infected by spyware, and claiming that a product called Spyware Cleaner was the cure.

A lawsuit filed by Washington State Attorney General Rob McKenna stated that Spyware Cleaner falsely claimed that computers were infected in an attempt to encourage PC users to pay $49.95 for a 'fully working' version.

According to court documents, Chen sent out emails and advertisements promoting Spyware Cleaner in exchange for a 75 per cent commission on each sale.

A number of other people are also facing charges of spamming and using nefarious and deceptive marketing practices to promote the software.

"Many computer users live in fear of spyware and viruses, and if they receive a legitimate looking warning message they could easily follow the advice to purchase clean-up software," said Graham Cluley, senior technology consultant at Sophos.

"Displaying a bogus detection message on an innocent person's computer with the intention of selling software is simply despicable.

"Let this be a warning that the authorities are prepared to investigate and punish those who engage in this kind of criminal activity.

"Several criminal gangs are in the business of persuading people to download software by misrepresenting a program as necessary to protect a computer's security or privacy."