The senator leading a probe into Brazil's handling of the COVID-19 pandemic has recommended that President Jair Bolsonaro be charged with homicide over what his report says are government errors that led to the deaths of thousands.

Bolsonaro has dismissed the probe as politically motivated. It is highly unlikely that he will face a trial on any such charges, which would have to be brought by Brazil's prosecutor general - a presidential nominee whom he appointed.

The nearly 1,200 page document, prepared by opposition Senator Renan Calheiros, alleges that Bolsonaro deliberately turned down early offers to purchase vaccines, delaying Brazil's inoculation campaign and costing an estimated 95,000 lives.

The report says Bolsonaro was guided "by an unfounded belief in the theory of herd immunity by natural infection and the existence of a treatment."

"Without the vaccine, deaths would be stratospheric, as they turned out to be," the report adds.

The draft report still needs to be voted on by the Senate and could be vetoed and altered. The vote is scheduled to take place next week.

The presidency did not immediately respond to a request for comment.

Earlier on Tuesday, Bolsonaro told supporters the probe was a "joke" and said he was not concerned about it.

At over 600,000 people, Brazil has the second-highest death toll worldwide due to COVID-19, behind only the United States.