Microsoft is fuming after its top secret new version of its Windows Mobile 6.5 operating system was pickpocketed at the  Mobile World Congress in Barcelona.

The phone was on loan to Telstra chief executive Sol Trujillo who was at the conference and testing it out, but it seems that it was in the hands of another Telstra executive at the time of the theft.

If the pickpocket knows anything about technology then it is possible to make a fortune on the black market with the phone and its new operating system.

Microsoft wants Windows Mobile 6.5 to give it an edge over new competitors such as the iPhone and Google's Android operating system. The delightfully understated Microsoft chief executive Steve Ballmer unveiled Windows Mobile 6.5 for the first time at the congress this week and it should be in the shops in June.

A spokeswoman for Microsoft played down the whole thing saying that its loss will not impact Redmond in anyway. Apparently pickpocketing, theft and street crime are so bad at the congress, organisers are thinking of moving it to another city.