A Brazilian Supreme Court judge has opened an inquiry into Elon Musk after the multi-billionaire said he would reactivate accounts on the social media platform X, formerly Twitter, that the judge had ordered to be blocked.

Mr Musk posted on the platform that the restrictions had been lifted because the court order was unconstitutional.

He also called for Justice Alexandre de Moraes to "resign or be impeached".

If X fails to comply with the order, it will be fined 100,000 reais ($19,774; £15,670) a day.

In his decision, Justice Moraes wrote that Mr Musk had launched a disinformation campaign against the Supreme Court.

The platform's Global Government Affairs team said the company was not allowed to say which accounts were affected.

But Mr Musk has since posted that "X will publish everything demanded by [Moraes] and how those requests violate Brazilian law".

The profiles are believed to have been linked to far-right movements which posted content related to riots on 8 January last year when thousands of supporters of Brazil's former President Jair Bolsonaro stormed the country's Congress, the Supreme Court and the presidential palace.

Justice Moraes gained prominence after his decisions to restrict social media platforms in the country.

He is also investigating Mr Bolsonaro and his supporters for their roles in an alleged attempted coup d'état.

On Saturday, the former president posted a video of a meeting he had with Mr Musk in May 2022.

- Jair Bolsonaro: “ @elonmusk é o mito da nossa liberdade” (20/maio/2022). pic.twitter.com/U0rPKBVFEC

— Jair M. Bolsonaro (@jairbolsonaro) April 7, 2024

Hours earlier, Mr Bolsonaro also called on his supporters to gather on 21 April.

Meanwhile, Brazil's communication minister Paulo Pimenta criticised Mr Musk, posting in capital letters that "social networks are not a lawless land".

"We will not allow anyone, regardless of the money and power they have, to affront our homeland," he added.

O Ministro Alexandre de Moraes determinou a abertura de inquérito para investigar a conduta do bilionário Elon Musk. Ele também ordenou que a rede X não desobedeça nenhuma ordem da Justiça brasileira. Na decisão, Moraes escreve, em letras maiúsculas:
"AS REDES SOCIAIS NÃO SÃO…

— Paulo Pimenta (@Pimenta13Br) April 8, 2024

If X decides to disobey the order, the platform could be blocked temporarily according to Bruna Santos who is the global campaigns manager at non profit organisation Digital Action.

"Musk acted to provoke the Brazilian judiciary," she said. "I think there is a real chance that X might get blocked."