Pirated versions of Microsoft's next generation computer operating system are on sale in Malaysia, more than a year before the official release date.
Bill Gates says Longhorn will be the decade's largest software launch
Copies of the software, codenamed Longhorn, have been found in the southern Malaysian city of Johor Baru costing less than $2.
Software industry sources told the BBC it was the piracy coup of the decade.
The new programme, which is due to supersede Windows XP, is not expected to be officially released before 2005.
Malaysian pirates are among the worlds most audacious. Major Hollywood movies can regularly be found on sale here in disc form long before their international premieres.
But this is possibly the pirates boldest move to date.
Microsoft is the world's largest computer software company and the unveiling of their next operating system is expected to be their largest software launch of the decade.
A Microsoft spokesman told the BBC they believe pirates obtained one of 8,000 trial copies of Longhorn handed out to programmers at a conference in Los Angeles in October.
The software is still in an early stage of development known as pre-alpha. The company says it would be extremely risky to load the still unstable operating system onto a home computer.
Malaysia is a major centre for intellectual property piracy and the government has been under pressure from Washington to do more to combat the problem.
In May, the Malaysian authorities shut down scores of shops selling pirated films. However those selling illegal copies of computer software seemed to escape more lightly.
The country's domestic trade ministry subsequently announced it was considering bringing down the price of legitimate software by imposing price controls - a move the industry said would lead to major players like Microsoft withdrawing from Malaysia entirely.