Twitter removed a false tweet by Donald Trump’s personal attorney Rudy Giuliani touting one of the president’s favorite, untested drugs to battle COVID-19.

Giuliani quoted parts of another tweet from a right-wing conspiracy theorist falsely claiming that the drug hydroxychloroquine proved to have a “100% effective rate treating COVID-19,” according to a screenshot of the deleted tweet in Mediaite.

The drug is only beginning to be tested in trials for COVID-19 and has not been approved for use against the novel coronavirus by the federal Food and Drug Administration. It’s currently used to treat malaria, lupus and arthritis.

Giuliani also attacked Michigan’s Democratic Gov. Gretchen Whitmer, whom he falsely accused of “threatening doctors” who prescribe hydroxychloroquine.

Trump last week touted hydroxychloroquine in combination with antibiotic azithromycin as a “game-changer” in the fight against COVID-19. But concerned doctors immediately warned that the drug combination can trigger fatal cardiac arrhythmia — a risk particularly problematic for senior citizens, especially those with heart problems.

🛑Hydroxychloroquine (plaquenil) can prolong the QT interval (heart rhythm) and can cause a FATAL arrhythmia. Azithromycin can also prolong the QT interval, so use of these 2 drugs together should ONLY be done under the supervision of a doctor. pic.twitter.com/ghtYMmFjBA — Dr. Dena Grayson (@DrDenaGrayson) March 21, 2020

Twitter confirmed to Mashable that Giuliani’s tweet was removed Friday and his account temporarily locked for violating the company’s rules against COVID-19 misinformation.

Twitter prohibits “content that goes directly against guidance from authoritative sources of global and local public health information,” including “description of treatments or protective measures which ... are being shared with the intent to mislead others.”

Earlier this week an Arizona man died and his wife was in critical condition from ingesting chloroquine phosphate — which is used to clean fish tanks — after Trump touted chloroquine as a treatment for COVID-19. The wife, who later recovered, said she and her husband took the fish-tank cleaner after they spotted the same ingredient in the contents that Trump was raving about on TV.