Microsoft sues Google over 'tapping up' of  Dr Kai-Fu Lee ex-corporate vice president of Microsoft's Interactive Services Division, someone considered privy to top level insider information at the company.

Dr Kai-Fu Lee  is one of the worlds top researchers in the field of speech recognition which is critical to the future success of natural language search. It is believed Microsoft viewed him as key in their search engine war with Google.

His new role at Google will see him heading up their operations in China.

A Microsoft spokesman said:

"As a senior executive, Dr Lee has direct knowledge of Microsoft's trade secrets concerning search technologies and China business strategies. "He has accepted a position focused on the same set of technologies and strategies for a direct competitor in egregious violation of his explicit contractual obligations."

The law suit aims to enforce Microsoft's confidentiality and non-competition agreements which it is believed Dr Lee broke in  his rapid departure from the company.