Though there have been reports galore that the smartphones running Windows Mobile 6. X ‘will not be upgradable’ to Microsoft’s February 15-unveiled new operating system Windows Phone 7 Series, the company itself has thus far refrained from officially confirming the reports.

Nonetheless, in what can be perceived as an inadvertent revelation, an article in APC magazine quoted Natasha Kwan, Microsoft’s general manager of Mobile Communications Business in the Asia-Pacific region, as saying that “because we have very specific requirements for Windows Phone 7 Series, the current phones we have right now will not be upgradable.”

Furthermore, the article also suggested that even the HTC HD2 smartphone, which features full touchscreen to meet the criteria for supporting the touch-centric interface of the Windows Phone 7 Series, might also not be upgradable as it has five buttons in place of three buttons – Home, Search and Back – that Microsoft has apparently asked its hardware manufacturers to restrict the form-factor of their devices to.

However, the supposed quote by its Asia-Pacific region executive has been rebuffed by a Microsoft spokesman who wrote to eWEEK that the company is insisting on some stringent hardware requirements so that the Windows Phone 7 provides a “consistently great experience” for end-users and developers.

The spokesman also said that Microsoft cannot yet confirm whether or nor the WM6. X phones meeting the requirements will be upgradable.