Microsoft claims that a small group led by a recently jailed Taiwanese man was the source of almost all high quality pirated copies of its software up until his arrest in 2004.

The claim suggests that Microsoft practically wiped out commercial piracy of its products with the arrest of Huang Jer-sheng, the owner of Taiwan-based software distributor Maximus Technology.

Microsoft announced today that Huang and his associates were responsible for the "production and distribution of more than 90 per cent of the high-quality counterfeit Microsoft software products either seized by law enforcement or test-purchased around the world".

Huang was recently sentenced to four years in jail by a Taiwanese court. Three co-defendants received between 18 months and three years in jail. Six individuals were originally arrested in the case.

Microsoft named two CD replication plants in Taiwan (Chungtek Hightech Enterprise and Cinway Technology) as the main producers of CDs for the piracy ring. Counterfeiters in southern China were also involved.

"After Chungtek was raided for intellectual property infringements in October 2001, Maximus ended the partnership and shifted its illegal operation to underground optical disk plants in the Shenzhen and Dongguan areas," said Taiwan's Intellectual Property Office.

Even holographic labels were duplicated. "A laser label expert was hired to conduct technology transfer of copying laser labels of the legal products," Taiwanese authorities reported after Huang was arrested.

"The finished products with their professionally made packaging, laser labels, warranty cards and instruction manuals made them impossible for consumers to question their authenticity."

Microsoft said in a statement released today: "The prosecutions of this international ring of counterfeiters, led by Huang Jer-sheng, mark the culmination of a number of complex global investigations conducted over a six-year period which resulted in the total dismantling of this criminal counterfeiting syndicate."