According to Chinese media reports, Beijing-based enterprise IT service provider and Microsoft customer Baihui Zongheng Technology has sought proof from Microsoft to confirm that it has legal permissions for operating in the country; and has also said that the software giant could otherwise face the risk of Office 365 being blocked.

As per the reports, which have been translated by Beijing-based tech consultancy Marbridge Consulting, Baihui Zongheng made the calls to Microsoft - to show its licence for Office 365 - at a Thursday press conference held at the China National Convention Center in Beijing.

Baihui Zongheng has released an open letter asking Microsoft to provide proof of its legality in China; and has also called on tech businesses to ensure that they were operating their cloud computing services "in compliance with the law" of the country.

In its letter, Baihui Zongheng has asked US-based Microsoft to show evidence that it has a license for operating commercial Internet information services in China. The evidence will prove whether or not Microsoft is legally permitted to operate a cross-border telecoms service.

Meanwhile, allaying the possible blocking-related fears of the Office 365 users in China, an IDC analyst told The Reg that "Microsoft would have double-ticked all the boxes before doing the 21Vianet deal;" and added "unless a Chinese customer takes the second option [served from data centres outside of China], there should be no risk of having access blocked."