Investigators raided the Mercedes Benz office in Shanghai on Monday as part of a wider anti-trust campaign in the country. Mercedes Benz

The South China Morning Post has reported that Chinese investigators raided Mercedes-Benz' Shanghai office on Monday morning as part of a broader anti-monopoly campaign in the country.

According to reports, the investigators arrived at the office at 10 a.m. local time, and successfully entered the building despite attempts from security guards to stop them. They remained until 9 p.m., questioning staff members and inspecting computers for data.

The investigation came as Daimler AG, Mercedes-Benz' parent company, announced that Mercedes would decrease prices on more than 10,000 spare parts by 15 percent, just a month after the luxury car brand cut service charges by 20 percent. China's anti-monopoly campaign, which began in 2008, has led other foreign auto manufacturers such as Audi and Jaguar to enact similar cuts.

Several iconic foreign brands have endured difficulties in China this year; last month, anti-trust investigators raided Microsoft offices in four Chinese cities, while police in Beijing have detained Steven Cao, the China boss for the American public relations firm Edelman, as part of an anti-corruption campaign.