Elon Musk said he closed the Brazilian office of his social network X on Saturday because a Brazilian Supreme Court judge ordered the company to suspend certain accounts or face the arrest of its legal representative in Brazil.

X said its service would remain available to users in Brazil. The company did not say how many people it employed in Brazil.

The move is a sharp escalation in Mr. Musk’s monthslong feud with the Brazilian judge, Alexandre de Moraes, whom he has accused of silencing conservative voices online. Mr. Moraes has said he is cleaning up the internet by removing misinformation and attacks on Brazilian institutions.

What is the fight about?

For the past several years, Mr. Moraes has ordered social networks to suspend hundreds of accounts and posts for spreading content that he says threatens Brazil’s democracy. His orders are typically sealed from public view and do not explain what an account did to warrant suspension.

Those orders have largely targeted right-wing supporters of Jair Bolsonaro, Brazil’s former president, including some who questioned Mr. Bolsonaro’s 2022 election loss and sympathized with protesters who raided Brazil’s Congress, Supreme Court and presidential offices in a bid to invoke a military takeover. Mr. Moraes has also overseen several criminal investigations into Mr. Bolsonaro and his allies.

That has made Mr. Moraes one of Brazil’s most powerful and polarizing figures. On the left, he is considered a hero; on the right, a villain.

In recent months, he has also become one of Mr. Musk’s most frequent targets. Mr. Musk has criticized Mr. Moraes dozens of times in posts on X, saying the judge’s orders are censorship and break Brazilian law.

Mr. Moraes declined to comment via a spokeswoman. Mr. Moraes has said that Brazilian law empowers him to block content online in order to protect the country’s institutions from what he has called a dangerous threat from some of Mr. Bolsonaro’s supporters.

“Freedom of speech is not freedom of aggression,” he said in April.

What led Musk to pull out of Brazil?

In recent days, X’s government affairs team published images of what it said were Mr. Moraes’s orders to remove at least 19 accounts, including those of right-wing influencers and a federal lawmaker.

In one document dated Friday, Mr. Moraes told the company that it had not complied with a takedown order. The judge said the company faced fines or the potential arrest of its legal representative in Brazil.

In 2016, Brazilian federal police officers arrested a local executive of Facebook because the company did not comply with a court order.

On Saturday, X’s official government affairs account posted that “to protect the safety of our staff, we have made the decision to close our operation in Brazil, effective immediately.”

The account added: “The people of Brazil have a choice to make — democracy, or Alexandre de Moraes.”

Mr. Musk quickly weighed in, saying that if his company complied with Mr. Moraes’s orders, “there was no way we could explain our actions without being ashamed.” He also called for the judge’s removal and mocked his appearance, comparing him to the “Harry Potter” villain Voldemort.

Brazil’s Supreme Court declined to comment on the documents published by X or the criticism.

Mr. Musk has had a big effect on Brazilian politics.

After Mr. Bolsonaro’s 2022 election loss, his far-right political movement had been sputtering. He had been ruled ineligible to run in the next election and was under investigation in several cases that could lead to prison time. He and his supporters were struggling to find a voice.

Then Mr. Musk arrived with a torrent of posts harshly criticizing Mr. Moraes. Over 17 days in April, Mr. Musk posted about Mr. Moraes more than two dozen times, calling the judge a dictator and comparing him to Darth Vader. Brazilian magazines and newspapers put Mr. Musk and Mr. Moraes on their covers, and the issue was debated in Brazil’s Congress.

Several U.S. House Republicans then also got involved.

The House Judiciary Committee, led by Representative Jim Jordan, Republican of Ohio, published sealed court orders from Mr. Moraes and accused him of leading a “censorship campaign.” In May, a House Foreign Affairs subcommittee held a hearing on the issue, which was frequently interrupted by cheers and boos from Mr. Bolsonaro’s supporters.

Over the past week, one of Brazil’s top newspapers, Folha de São Paulo, has published a series of articles written in part by the American journalist and pundit Glenn Greenwald, who lives in Brazil and has been one of Mr. Moraes’s loudest critics. The articles used leaked text messages to show how Mr. Moraes and his colleagues worked behind the scenes to suspend accounts. In some cases, the messages suggest that Mr. Moraes targeted specific accounts and asked officials to find justification to suspend them.

In response to the articles, Mr. Moraes said that he had always acted within the law, against accounts that spread anti-democratic messages, hate speech and attacks on Brazil’s Supreme Court, including death threats.

In Brazil, the attention from the United States helped rejuvenate the nation’s right-wing movement — particularly its efforts to target Mr. Moraes. On Saturday, Mr. Musk shared a prominent Brazilian congressman’s call for a march to demand Mr. Moraes’s impeachment.

Mr. Musk has increasingly used his enormous platform on X to boost certain politicians, including Donald J. Trump and President Javier Milei of Argentina, while getting into spats with others, as when he recently criticized Prime Minister Keir Starmer of Britain over protests in the country.

What could happen next?

While X said Brazilians could continue to use its social network, Mr. Moraes could move to block the service in Brazil if the company does not comply with his orders.

In 2022, Mr. Moraes announced a ban in Brazil on the messaging app Telegram because he said the company ignored court orders. After the company quickly responded, he dropped plans for a ban.

Mr. Musk has said that he plans to stand up against Mr. Moraes even if it hurts X’s business. The company has not disclosed how many users it has in Brazil, but analysts have said it is one of the company’s largest markets.