The fraud concerned invalid national vocational qualification certificates. As a result of the police investigation 1,669 NVQs in motor industry-related subjects, such as mechanical and electrical repair and bodywork, were withdrawn.
Detective Sergeant Rob Vick, of West Mercia police, who led the four-year investigation, said: "The defendants in this case not only benefited financially but could have put lives at risk by awarding NVQ certificates for candidates to work on motor vehicles, when they had not been shown to have reached the required standard of achievement."
The certificates were awarded by the Road Transport Industry Training Board Services, which had set up its own training company, Centrex. Some 150 people lost their jobs when the training provider went out of business. The cost of the fraud was pound;4.3 million.
Coventry and Warwick Training and Enterprise Council first raised their concerns about the reliability of the certificates in 1995.
Ken Boston, chief executive of the Qualifications and Curriculum Authority, said: "All qualification systems rely upon the honesty and integrity of those involved, without that there can be no public trust in the value of the awards."