The Brazilian judiciary is to investigate President Jair Bolsonaro for making false statements about the coronavirus pandemic.
The move was ordered by a judge at the country's Supreme Court, according to a statement issued on Friday.
In a live broadcast on social media in October, Bolsonaro made a connection between the Covid-19 vaccination and AIDS.
Bolsonaro has played down the virus since the beginning of the pandemic and rejects protective measures and restrictions.
He also doubts the point of vaccinations. He is accused of having refused and delayed the purchase of vaccines.
According to official figures, more than 22 million people in Brazil have been infected with the coronavirus, and more than 615,000 patients have died in connection with Covid-19 - only the United States has more deaths.