One of China's most popular microbloggers warned of the dangers of "casual" online posts in an interview with state-run media on Wednesday, as authorities continued a crackdown on Internet speech.

State-broadcaster CCTV asked Pan Shiyi, who has more than 16 million followers on Sina Weibo, China's wildly popular equivalent of Twitter, to describe the "social responsibility" of microbloggers.

Pan, a wealthy real-estate developer who has become an influential leader of public opinion through his online comments, said that popular microblog users should be "more disciplined".

"If we are post completely casually...then the social impact and damage will be large," he said.

Chinese authorities have launched a high-profile effort to control speech on microblog platforms in recent months, after they became a key force shaping opinion amongst China's more than 500 million Internet users.

Police have detained hundreds for posting information deemed to be "false", according to reports.

The campaign has also focused on celebrity microblog users, who were summoned for a meeting at the offices of CCTV in August and told not to post information that conflicted with the "national interest", according to state-media.

New regulations posted by China's Supreme court this week said Internet users could face three years in jail if slanderous information spread online is viewed more than 5,000 times or forwarded more than 500 times.

China's state-run media has said the campaign is aimed at combating online fraud and defamation, but activists say political speech has been targeted in the crackdown.

Posts on Chinese microblog platforms have long been censored at the request of authorities, but are subject to less-strict controls than print media.

Analysts say China's ruling Communist party has been worried by its relative lack of ability to control the spread of information on microblog platforms, which have been used to expose official graft and incompetence.