Facebook and Twitter have removed videos of Brazilian president Jair Bolsonaro endorsing the anti-malarial drug hydroxychloroquine as a COVID-19 treatment.

Social media companies have been reluctant up until now to act on misinformation from politicians, classifying even lies as free or political speech.

Hydroxychloroquine is currently being studied to see whether it can be used to treat COVID-19 but, according to the CDC, its efficacy is still unproven.

President Trump has also praised hydroxychloroquine and asked the FDA to fast-track access to the drug.

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Facebook and Twitter have taken action on a video from Brazilian president Jair Bolsonaro, removing it for infringing on their misinformation policies.

The video, as reported by BBC News Brasil, showed Bolsonaro talking to a street vendor and endorsing an anti-viral drug called hydroxychloroquine as a COVID-19 treatment.

"This medicine here, hydroxychloroquine, is working in every place," Bolsonaro claimed, incorrectly.

The Brazilian president has consistently downplayed the threat of the coronavirus, telling the nation it is "just a little flu or the sniffles," and consistently going out in public.

Bolsonaro's communications aide tested positive for the coronavirus earlier in March, and the president has claimed he tested negative for the virus despite their proximity.

Hydroxychloroquine is an antimalarial drug and has also been endorsed by President Donald Trump, who told the FDA to fast-track emergency experimental treatment of the drug.

The Centers for Disease Control and Prevention says hydroxychloroquine has not yet been proven to be an effective treatment for coronavirus.

Facebook confirmed to Business Insider that it had removed the video. "We remove content on Facebook and Instagram that violates our Community Standards, which do not allow misinformation that could lead to physical harm," a spokeswoman said.

It's a substantial step for social media firms that have so far been reluctant to delete posts from politicians, classifying even lies as political or free speech issues. Facebook especially has been excoriated for permitting political lies on its platform.

Twitter was not immediately available for comment when contacted by Business Insider, but a spokesman told Bloomberg: "Twitter recently announced the expansion of its rules to cover content that could be against public health information provided by official sources and could put people at greater risk of transmitting COVID-19."

Twitter also told NBC that it required Bolsonaro to take down the video himself to carry on using the platform. BuzzFeed reports Twitter also removed a tweet containing a video of Bolsonaro calling for an end to social distancing.

The CDC warned on Saturday against taking various forms of chloroquine. "Currently, these medications are being studied and evaluated as treatment for COVID-19; however, their efficacy to either prevent or treat this infection are unknown," it said.

Last week an Arizona man died after ingesting chloroquine phosphate, and his wife said she and her husband had taken it after "Trump kept saying it was basically pretty much a cure."

Medical facility Banner Health said the pair had ingested a form of the chemical commonly used to clean aquariums.

"Don't take anything. Don't believe anything that the president says and his people... call your doctor," the wife said.