Chinese authorities have said that Microsoft has so far not fully complied with the government's anti-monopoly investigation, and is seeking more information about its media player and Web browser distribution.

Microsoft's media player and internet browser are the focus in a Chinese antitrust probe, providing a further glimpse into an investigation that led to surprise inspections of Microsoft's China offices in recent weeks.

According to Zhang Mao, who is the head of State Administration for Industry and Commerce, Microsoft Corp has not been transparent with information about its Office and Windows sales, but the company is willing to cooperate with ongoing investigations.

As Windows became the world's top operating system (OS) during the 1990s and 2000s, the issue of how the company bundled its media player and web browser became the focus of antitrust cases brought by European and U.S. authorities.

The company settled a long-running case with the U.S. Department of Justice in 2001, which centered on whether it could bundle its flagship Internet Explorer (IE) browser with Windows.

The European Union (EU) ordered the company to pay a 497 million euro penalty in 2004, and produce a version of Windows without Windows Media Player bundled. Moreover, the penalty was later increased to almost 1.4 billion euros.

The investigation comes, when other antitrust probes against foreign companies in China are being conducted, including German car maker Daimler AG's luxury auto unit Mercedes-Benz and mobile chipset maker Qualcomm Inc. The investigations have sparked fears of Chinese protectionism.

Microsoft had been suspected of going against China's anti-monopoly law since June 2013 with respect to problems with bundling, compatibility and document authentication for its Windows OS and Microsoft Office software, SAIC, one of China's anti-monopoly regulator said.