President Vladimir Putin in September granted Russian citizenship to Snowden, who fled the US after leaking secret files that revealed the extensive eavesdropping activities of the US and its allies.

Snowden fled the US and was given asylum in Russia after leaking secret files in 2013 that revealed vast domestic and international surveillance operations carried out by the NSA, where he worked.

In early January, after the information on 'SARS cases' was shared in a WeChat group, Li was reportedly reprimanded by the local police.

The former Facebook engineer leaked a trove of internal documents that have sparked weeks of criticism of the social media giant and a major push worldwide to get tough on big tech.

The former employee, who accused the social media giant of putting profit before people at a Senate subcommittee earlier this month, says she is encouraged by British plans to force big tech companies to tackle harmful content on their platforms.