BEIJING (Reuters) - A popular internet microblogger confessed in court to spreading rumours about the Chinese government, the official Xinhua news agency reported on Friday, in the first public trial since China began cracking down on online rumours last year.

Rights advocates say China's campaign to quash online rumours, which began last summer, is tantamount to crushing free expression. The government says the crackdown is necessary to preserve social stability.

Online rumours are particularly pervasive in China, where traditional media is heavily regulated by the government and public trust in the media is low.

Qin Zhihui invented a story that the Chinese government gave 200 million yuan (S$40 million) in compensation to the family of a foreign passenger killed in a high-speed train crash in 2011, Xinhua said.

He posted the rumour on Weibo, China's Twitter-like microblog, and the story was shared widely by other microblog users, Xinhua said.

According to the Xinhua report, Qin also told false stories about a popular television starlet and other celebrities.

No comment was available from Qin and Xinhua gave no indication of any defence he raised in court. The trial is continuing, Xinhua said.

The ruling Communist Party's campaign to control online discourse threatens criminal penalties against those who spread rumours on microblogs that are reposted more than 500 times or seen by more than 5,000 users.