Facebook owner Meta Platforms Inc (FB.O) said on Wednesday it had removed accounts used by an influence operation originating in China that promoted claims of a fake "Swiss biologist" saying the United States was interfering in the search for Covid-19's origins.

Meta said in a report the social media campaign was "largely unsuccessful" and targeted English-speaking audiences in the United States and Britain and Chinese-speaking audiences in Taiwan, Hong Kong and Tibet. Claims by "Swiss biologist" Wilson Edwards were widely quoted by Chinese state media in July. In August, several Chinese newspapers removed comments and deleted articles quoting him after the Swiss embassy in Beijing said it had found no evidence of him as a Swiss citizen.

Meta said Facebook removed the Wilson Edwards account in August and has since removed 524 Facebook accounts, 20 Pages, four Groups and 86 Instagram accounts as part of its investigation. Such removals also take down content that these entities have posted. "We...were able to link the activity to individuals in mainland China, including employees of a particular company in China, the Sichuan Silence Information Technology Company Limited, as well as some individuals associated with Chinese state infrastructure companies around the world," Meta's head of global threat disruption David Agranovich told Reuters.

Sichuan Silence Information Technology Co did not immediately respond to a request for comment. The Chinese foreign ministry and internet regulator Cyberspace Administration of China also did not immediately respond to requests for comment.

Meta said it had not found any connection between Sichuan Silence Information Technology and the Chinese government.