Facebook (now known as Meta) has removed hundreds of accounts linked to China-based administrators for allegedly promoting coronavirus misinformation online, the U.S.-based social networking site said Thursday.

Meta, formerly known as Facebook Inc., said it deleted “524 Facebook accounts, 20 pages, four Groups and 86 Instagram accounts” connected to the misinformation campaign.

The operation launched on July 24 involved a social media user posing as a fake Swiss biologist named “Wilson Edwards” who claimed on Facebook and Twitter that the U.S. government was “putting pressure on World Health Organization [W.H.O.] scientists studying the origins of COVID-19 [Chinese coronavirus] in an attempt to blame the virus on China,” Facebook detailed in a report published December 1.

“Within 48 hours, hundreds of social media accounts around the world had picked up on the story. Within a week, Chinese state media including the Global Times and People’s Daily were running headlines about the alleged US ‘intimidation,'” Facebook recalled.

“On August 10, the Swiss Embassy in Beijing announced that there was no record of any Swiss citizen by that name [“Wilson Edwards”]. The same day, we investigated and removed the Facebook account as fake,” the company detailed.

“Looking for Wilson Edwards, alleged [Swiss] biologist, cited in press and social media in China over the last several days. If you exist, we would like to meet you! But it is more likely that this is a fake news, and we call on the Chinese press and netizens to take down the posts,” the embassy of Switzerland in China wrote in a Twitter statement August 10.

“Although most people behind this conspiracy-peddling network tried to conceal their identities and coordination, the [Meta] researchers found links to individuals in … China,” Britain’s Independent newspaper noted on December 2.

“They said accounts linked to employees of information security firm Sichuan Silence Information Technology Co Ltd were also involved, as well as individuals associated with Chinese state infrastructure companies located around the world,” the newspaper observed.

Twitter in March suspended an “army” of fake bot accounts for allegedly violating the company’s rules about data “manipulation” by amplifying pro-Chinese Communist Party (CCP) propaganda.

“Covid-19,” or the Chinese coronavirus, is the name of the disease caused by SARS-CoV-2, which is a type of coronavirus. SARS-CoV-2 first emerged in Wuhan, China, sometime in late 2019 before quickly spreading nationwide. China’s epidemic soon spilled over the country’s borders to the rest of the world, causing a pandemic that remains ongoing today. Much about the virus’s origin remains unknown as China’s ruling Communist Party worked in tandem with the W.H.O. to play down the contagiousness and severity of illness caused by the then-novel coronavirus during the early weeks of Wuhan’s epidemic. This cover-up coincided with a general obfuscation of SARS-CoV-2’s provenance by CCP authorities.

The W.H.O. sent a team of researchers and scientists to Wuhan in January to investigate the origins of the Chinese coronavirus pandemic. The mission was delayed for months by CCP officials who made the team’s entry to China extremely difficult and often voiced public opposition to the probe, claiming it was unnecessary. The hindrances cost the W.H.O. team valuable time as original samples of the virus procured from some of China’s first SARS-CoV-2 patients were at risk of being too old for viable examination once the researchers finally arrived, over a year after Wuhan’s initial outbreak.

The W.H.O., which is the United Nations (U.N.)’s public health agency, published a report in March saying its investigation was “inconclusive.”

“We have not yet found the source of the virus, and we must continue to follow the science and leave no stone unturned as we do,” W.H.O. Director-General Tedros Adhanom Ghebreyesus told reporters shortly after the report’s release on March 30.

“In my discussions with the team, they expressed the difficulties they encountered in accessing raw data. I expect future collaborative studies to include more timely and comprehensive data sharing,” he said, referring to China’s interference in the probe.

The W.H.O. announced on October 13 it planned to establish a new scientific group to study SARS-CoV-2’s origin a second time.