China is tightening its grip on its domestic Internet as it introduces police officers into the buildings of major networking companies in the country.

Firms like Tencent and Alibaba are likely to be among those affected by the plans from the Ministry of Public Security, which controls law enforcement throughout China and has a history of interfering with Chinese communications.

Chen Zhimin, deputy minister at the body, told a conference on Tuesday: "We will set up ‘network security offices’ inside important website and Internet firms, so that we can catch criminal behavior online at the earliest possible point."

He argued that as China entered the Internet era, network security has become a matter of national security and social stability, which in turn influences the country’s economic development.

Among the crimes the Chinese police are looking to stop are network intrusion, theft of personal data, fraud and the sharing of illegal information, which can include pornography or details of weapons.

Chen hoped his plans would create a "model of social responsibility, sincere treatment, and properly handled complaints of Internet users, allowing network to discover evidence of crime".

In the past China has earnt infamy in the West for its so-called "Great Firewall", a system by which the Chinese Communist Party can regulate what content can be viewed from inside the country.

Other Internet laws mean that firms such as Baidu, the Chinese equivalent of Google, are forced to screen online content for pornography and anti-Communist statements.

The difference in values even led Google to retreat from the Chinese mainland to Hong Kong in protest, with the search engine one of many technology companies that has had disputes with China.

Foreign firms’ difficulties in compliance and the huge population in the country has allowed domestic Chinese companies to grow to an impressive scale, with Alibaba threatening the American ecommerce firm Amazon in other regions.