The surreal standoff is the latest flashpoint in a broader battle between a president who has repeatedly tested the limits of his power and democratic institutions.

Mr Bolsonaro has consistently downplayed the coronavirus pandemic and has fiercely criticised efforts by governors and mayors to impose measures to control the spread of the virus, instead advocating for most people to get back to work.

But the courts have repeatedly curtailed him.

They ruled that governors and mayors have the power to determine shutdown measures, overturned the president's decree allowing religious gatherings and are trying to force the release of his Covid-19 test results to end speculation he may have lied.

Mr Bolsonaro's supporters have denounced the decisions as part of a plot to derail his presidency, and the president himself said he is a victim of meddling by obstructionist judges.

He said: "Enough with the interference. We're not going to allow any more interference.

"Patience has run out. We're going to take Brazil forward."

The fight over his coronavirus test results has produced a particularly unusual chapter.

Concerns about Mr Bolsonaro's health began in March, when the president returned from the US, and local media reported in the weeks that followed that more than a dozen members of his delegation tested positive for the coronavirus.

Initial unconfirmed reports indicated Mr Bolsonaro had tested positive himself but then he announced on social media that his results had come back negative.

He has refused to produce the actual document, citing medical privacy.

Last week, a federal judge in Sao Paulo ordered Mr Bolsonaro to present the results in response to a request from the O Estado de Sao Paulo newspaper.

Mr Bolsonaro's attorney-general instead sent a summary of the results, the office said in a statement.

The judge again insisted on the actual results, and a separate judge on Saturday gave Mr Bolsonaro's team five days to comply.

Mr Bolsonaro has also further muddied the waters recently. Following the lawsuits, he said last week he had "perhaps" contracted the virus without knowing it.

However, he has kept appearing in public without a mask, addressing crowds and shaking well-wishers' hands - on one occasion, after wiping his nose.

Australian Associated Press