Brazil’s justice minister is facing growing calls to resign after a series of politically explosive leaks that some observers believe could have a profound effect on Brazilian politics and the administration of the far-right president, Jair Bolsonaro.

Sérgio Moro became an A-list celebrity in Brazil for leading the historic “Car Wash” anti-corruption investigation.

He controversially took his job last year after helping jail Bolsonaro’s key election rival, former president Luiz Inácio Lula da Silva, and has been widely tipped as a future president himself.

But Moro’s political future was thrown into doubt on Sunday after the Intercept began publishing a series of exposés based on what it called “a vast trove” of secret documents provided by an anonymous source.

The Intercept said its “Secret Brazil Archive” reports – which contained compromising excerpts from mobile phone chats between Moro and Car Wash prosecutors – showed he had engaged in “improper and unethical plotting” designed to ensure Lula’s imprisonment.

Lula was prevented from taking part in last year’s presidential election – which polls suggested he would have won – after being convicted of bribe taking and corruption by Moro in 2017. He is currently serving an almost nine-year sentence in southern Brazil.

Moro has rejected accusations of wrongdoing as “sensationalist” smears and his supporters branded the leaks a criminal conspiracy designed to undermine the former judge and Bolsonaro’s administration.

But on Tuesday – as Brazilian politicians braced for further revelations promised by the Intercept - there were calls for Moro’s removal.

“Moro has to go,” said Guilherme Boulos, a left-wing leader some see as a potential heir to Lula.

“There is now compelling evidence of his involvement in illegal and unethical practices … Moro no longer has the political or moral capacity to run the justice ministry.”

The conservative Estado de São Paulo newspaper said it believed Moro should resign.

The Intercept’s leaks revealed “a totally inappropriate – and possibly illegal – relationship” between Moro and prosecutors “with legal and political implications that are still hard to gauge”, the newspaper said in a scathing editorial.

“Other ministers have been sacked for far less,” it pointed out.

José Roberto de Toledo, a political journalist from the magazine Piauí, said he did not believe Bolsonaro would immediately dismiss his minister.

“But Moro’s image has been damaged and Bolsonaro is clearly on the defensive, not wanting to tie himself too closely to Moro because of the chance he might have to sack him,” Toledo said, pointing to Bolsonaro’s failure to personally defend Moro.

So far, Bolsonaro’s only public statement of support has come through a spokesperson who insisted Moro enjoyed the president’s “complete trust”.

“I don’t think he will fire him today,” Toledo said. “[But] until Sunday night if someone had said: ‘Bolsonaro might sack Moro,’ you’d have said: ‘You’re mad – you’re delusional.’ Today it’s a possibility – not a huge possibility but a possibility.”

Eliane Cantanhêde, a political columnist for the Estado de São Paulo, said Moro was likely to survive the Intercept’s disclosures thanks to his hero status among many Brazilians.

“Despite being detested by the left … Moro went down in history and became internationally known for running the greatest anti-corruption investigation in the world. He has immense popular support.”

“Does it look good for Moro? No it doesn’t … But is it enough to destroy his public image? I don’t think so,” she said.

But Cantanhêde sensed nervousness and caution in the capital, Brasília, that the Intercept might have “a bomb” up its sleeve. “Nobody wants to defend Moro only for more things to come out.”

Brian Winter, the editor-in-chief of Americas Quarterly, said it was possible the leaks could lead to Lula’s release.

“For this kind of conduct to have been revealed is at the very least devastating for the image of the Car Wash probe and it could also result in the nullification of the case against Lula,” said Winter, who knows Moro and expressed concern over his decision to take a job in Bolsonaro’s government last year.

The shockwaves would also be felt across the region, in countries such as Peru and Argentina where major corruption investigations linked to Car Wash are playing out.

“People in the anti-corruption community around Latin America were furious with Sérgio Moro when he accepted this job last year [because of the appearance of political impropriety] and they are 10 times as angry now … because it affects their work,” Winter said. “It allows the corrupt to say: ‘I am being unfairly targeted too.’”