The political whirlwind convulsing Brazilian politics has intensified with the supreme court approving an investigation into explosive allegations that the president, Jair Bolsonaro, illegally attempted to interfere in the federal police.

“The president of the republic … is also subject to the laws, just like any other of the country’s citizens,” the supreme court judge Celso de Mello noted in his decision on Monday night.

“No one, absolutely no one, is entitled to infringe and show contempt for our country’s laws and constitution.”

In a separate blow, a judge gave the federal government 48 hours to hand over the results of two Covid-19 tests Bolsonaro took last month but has refused to publish.

More than 20 members of a delegation Bolsonaro took to meet Donald Trump in early March were infected, fuelling suspicions that Brazil’s president – whose handling of the coronavirus crisis has been widely criticised – had also been contaminated.

Claims that Bolsonaro had improperly tried to meddle in Brazil’s equivalent to the FBI were made last Friday by Sergio Moro, the outgoing justice minister.

As he resigned from Bolsonaro’s cabinet, Moro issued a potentially devastating parting shot: publicly accusing his former boss of wanting to replace the head of the federal police with someone more amenable to discussing police business and sharing intelligence reports with the president.

“I said this would be political interference and he said it would indeed be,” claimed Moro, a former judge who many suspect harbours presidential ambitions of his own.

Two prominent Brazilian newspapers, the Folha de São Paulo and Correio Braziliense, have claimed Bolsonaro’s desire to remove the federal police director was driven by the knowledge that investigators examining the criminal dissemination of fake news were closing in on his son Carlos Bolsonaro.

Federal police investigators in Rio de Janeiro are also investigating another of the president’s sons, Flávio Bolsonaro, for suspected corruption and ties to Rio’s mafia.

On Tuesday, Bolsonaro’s pick for the new federal police director was officially announced: the intelligence chief Alexandre Ramagem, who is a friend of Carlos Bolsonaro. The appointment is expected to face legal challenges.

The far-right president and his sons deny the accusations against them.

On Tuesday, Estado de São Paulo claimed Moro would hand audio recordings to investigators as part of the inquiry into the president’s behaviour.

The possible crimes for which Bolsonaro will be investigated reportedly include fraudulent misrepresentation, obstruction of justice and passive corruption. Moro will be investigated for so-called “crimes against honour and reputation”, which include calumny and defamation.

Bolsonaro’s opponents – who decry his assaults on the environment, the arts and Brazil’s democracy – hope the investigation could eventually provide grounds for his impeachment. A poll on Monday suggested nearly half of Brazilians wanted Bolsonaro to resign – up from 37% last month, while 38% thought it was impossible to trust anything he said.

However, the poll also showed Bolsonaro continuing to enjoy the support of 33% of voters – a reality that suggests impeachment is unlikely in the short term. When the former leftist president, Dilma Rousseff, was impeached in 2016 her support had collapsed to only around 13%.

“He has already committed numerous crimes of responsibility – but for impeachment you need votes,” admitted Marcelo Freixo, a leftwing congressman from the Socialism and Liberty party.

“The whole of the left in parliament has 134 representatives. Bolsonaro has 210 on his side,” Freixo added. “I favour impeachment but being in favour of impeachment isn’t enough. You need the votes.”

Eliane Cantanhêde, a columnist for the Estado de São Paulo, predicted Bolsonaro would pay a heavy price for creating a political crisis at the very moment Brazil needed to focus on the coronavirus pandemic, which has now killed 4,603 Brazilians. “It’s insane ... It’s almost as if he’s asking to be impeached,” she said.

But Cantanhêde said she still was not convinced there was currently enough political or public support for such a move. “Can you imagine an impeachment at this juncture? It would be very, very traumatic – especially with the economy crumbling and everything upside down.”

Kim Kataguiri, a rightwing congressman who has been pushing for the release of Bolsonaro’s coronavirus test results, said the Brazilian people had a right to the truth. “This is a matter of public interest and must not be hidden … We need clarity,” said Kataguiri, who supported Bolsonaro before his 2018 election but has since turned on the president.

Bolsonaro, who has faced global condemnation for repeatedly undermining the social distancing guidelines promoted by his own health ministry, made no immediate comment about the supreme court investigation. Instead the pro-gun populist ventured out of his presidential palace in the capital, Brasília, on Tuesday to visit a shooting range.

In a video later posted on his official Facebook page, a grinning Bolsonaro appeared examining a bullet-riddled target. “Pretty good, eh?” he says.

