Google is launching a censored version of its search engine in China that will block access to sites including the BBC.

The internet giant will block access to sites banned by the country's ruling communist party, including Wikipedia and BBC News, according to leaked internal documents seen by The Intercept.

Sites and search terms about human rights, democracy and religion will also be blacklisted.

Campaign groups have criticised Google for hypocrisy and assisting oppression, arguing the move sets a dangerous precedent for other large organisations.

Google, however, is desperate to crack the lucrative Chinese market of 750m web users who could provide billions in revenue.

The Chinese search engine project, code-named Dragonfly, has been in development since last spring and could launch within six to nine months, according to the leaked documents.