Simon Vallor, a Web designer and part-time disc jockey from Llandudno, Wales, is due to be sentenced at Southwark Crown Court next week, after pleading guilty to writing and disseminating the destructive Gokar virus.
But police at Scotland Yard's Computer Crime Unit said they have had very little support from businesses in bringing the prosecution, despite widespread concern in the business community about the impact of computer viruses.
Detective superintendent Steve Santorelli said the police made extensive efforts to contact businesses that had suffered damage from the virus, but most claimed they were either unable or too busy to assist in the investigation.
"Only one person eventually went to the trouble of providing us with a statement. Many people we contacted did not want to get involved. They had cleaned and restored their systems and did not want to lose any more time assisting us with a statement," he said.
The revelation has highlighted concerns that computer criminals are escaping detection because of the unwillingness of businesses to report computer crimes or assist the police in gathering evidence.
Peter Sommer, security expert at the London School of Economics, said most firms would have been too concerned with getting their systems restarted to think about preserving evidence for a police investigation.
"If you are struck by a virus, your first inclination is to carry on working and sort the machines out. The thought that you might be able to contribute to a police prosecution looms low on your horizon," he said.
Police raided Vallor's home following a tip-off from the FBI. Detectives were able to trace his e-mail address back from postings on the Internet in which Vallor had boasted of writing the Gokar virus.
Vallor has been charged on three counts under section three of the Computer Misuse Act, each carrying a maximum penalty of five years imprisonment. A custodial sentence is thought unlikely, however.