China has made it a legal requirement for people signing up to new mobile phone and data plans to have their faces scanned, in a major growth of the surveillance state.

The new rules, outlined by China’s Ministry of Industry and Information Technology (MIIT), came into effect on Sunday.

They require new phone plan users to submit face scans alongside their national identification card information, ensuring their devices are linked to their real identities.

The MIIT said the move was made "to safeguard the legitimate rights and interest of citizens in cyberspace", and would help protect phone users from fraud.

With Chinese authorities cracking down hard on online dissent and arresting government critics, there are concerns that the regulations mark the next step in the Chinese Communist Party (CCP)'s construction of the world's most draconian surveillance regime.

Debate about the government’s intent with regard to the new requirement was sparked on Chinese social media sites, such as Weibo.