RIO DE JANEIRO, Brazil (AFP) – Under investigation in Brazil, X owner Elon Musk escalated his row with a Supreme Court justice Monday over alleged censorship of the social network, challenging him to a debate and mocking his disinformation crackdown.

The row erupted over the weekend, when Musk lashed out at crusading Brazilian Supreme Court judge Alexandre de Moraes, who has aggressively fought disinformation online — especially attempts by far-right supporters of ex-president Jair Bolsonaro to discredit the electoral system.

The Tesla and SpaceX boss said Moraes has “betrayed the constitution” by muzzling free speech, and “should resign or be impeached.” He threatened to defy court orders blocking users.

Moraes responded Sunday by threatening fines of around $20,000 each if X reactivates any blocked accounts, and ordered an investigation of Musk, accusing him of “criminal instrumentalization” of the platform formerly known as Twitter.

Musk fired back on X, writing: “What say you @Alexandre? Let us debate this in the open.”

He also jokingly imagined himself as Moraes’s psychoanalyst.

“Tell me, Alexandre, is the disinformation in the room with us now?” he wrote.

Moraes, 55, is a powerful, divisive figure in Brazil, where he is one of 11 Supreme Court justices and also presides over the Superior Electoral Tribunal.

Critics accuse him of censorship.

Right-wing politicians launched a manifesto defending Musk and backing his call for Moraes’s removal. “Impeachment” was a trending topic on X in Brazil.

Others defended Moraes.

Supreme Court Chief Justice Luis Roberto Barroso issued a statement warning that “any and all companies” operating in Brazil must obey its authorities.

He said “a life-and-death struggle for the democratic rule of law” had played out during Brazil’s 2022 elections, which Bolsonaro lost to veteran leftist Luiz Inacio Lula da Silva.

Bolsonaro, 69, is under investigation for allegedly plotting a coup to try to remain in power.

Senate president Rodrigo Pacheco meanwhile rejected the “censorship” label, urging lawmakers to regulate social media to stop abusers from “manipulating disinformation, spreading hate and violence,” in comments reported by news site G1.

South Africa-born Musk, 52, is known for his sometimes combative antics.

Last year, he challenged Facebook co-founder Mark Zuckerberg to a cage fight, after reports his fellow billionaire was working on a Twitter competitor.