The phenomenal growth of the Google search engine in China may be about to end, after authorities accused it of allowing access to pornography - a claim that observers see as pretext for a crackdown on internet freedom.

China wants to embrace new technology, but its authorities have a problem with unfettered internet access - to the extent that a huge and complex national internet filtering system has been dubbed the 'Great Fire Wall' of China.

Authorities have ordered Google China to disable some of its online functions, blocking access to overseas websites and raising renewed concerns over China's internet censorship.

Google's local version has more than 30 per cent of the Chinese search engine market, after the US-based company made agreements on content and censorship with the Chinese government.

But a student who appeared on China's most prominent, and Government-controlled current affairs program, claimed Google China was corrupting his classmates' minds.