A host of multi-national firms including the Microsoft, the mainstay of the country's IT boom, have faced anti-monopoly probes with raids on their offices.
The latest to face action was Mercedes Benz and Audi, which were inspected by state regulators, the official CCTV reported.
Nine anti-trust officials met with Mercedes executives in their Shanghai offices and "forcibly checked PCs," Daimler, maker of Mercedes-Benz and Smart cars, said.
CCTV said the investigation will focus on Mercedes and Audi price policy in China as well as its relationship with local dealers.
The companies were asked to follow a fixed price policy, it said.
Audi had cut prices for its spare parts last month.
The investigations reportedly focused on complaints against foreign car companies over charging their Chinese clients since June this year.
Mercedes has dropped prices of its spare parts twice in the last few months.
Also, China launched an anti-monopoly investigation against Microsoft questioning some of its top officials.
China's market regulator yesterday warned Microsoft not to interfere with an ongoing anti-monopoly probe.
Investigators from the State Administration for Industry & Commerce (SAIC) warned that the company must firmly abide by Chinese law and not interfere with the investigation "in any way".
SAIC confirmed that it launched a probe into Microsoft China Co. Ltd, and three of its branches in Shanghai, Guangzhou and Chengdu as the firm is suspected of monopoly practices.
Earlier, British drug maker Glaxo Smith Kline (GSK) was investigated over corrupt practices and two foreigners associated with it were put on trial.