Microsoft (Nasdaq: MSFT) is reportedly alleging that four China-owned companies are using unlicensed Office and Windows software. The Washington-based company has asked a Chinese government panel to put a stop to the alleged use by these companies of pirated software, according to a Bloomberg report citing three people who asked not to be named because Microsoft's filing isn't public.

Microsoft alleges wrongdoing by China National Petroleum, China Railway Construction, China Post Group, and Travelesky Technology. Each of the four companies utilizes significant amounts of pirated software, ranging from 40% to nearly 100%, according to Microsoft calculations reported by Bloomberg.

Its allegations have been called "inaccurate" and "greatly exaggerated" by Chinese company officials, according to Bloomberg.