Jair Bolsonaro has been detained after authorities found he posed a concrete flight risk while under house arrest.
The one-time leader was convicted of plotting a government overthrow in last fall and given more than 27 years in jail, but he continued under house arrest pending legal challenges.
High Court Judge the presiding justice said the decision to arrest the 70-year-old politician was a preventative measure after fresh information emerged.
This included seeking to disable his tracking device and a invitation to a supporters' gathering that could enable a potential flight.
Judicial Records Show Flight Fears
In a paperwork permitting the custody, Justice Moraes said information from the centre monitoring the former president's confinement suggested the one-time head of state's "intention to break the tracking monitor to secure accomplishment in his getaway".
This, it said, would be assisted by the confusion caused by the gathering called by his child.
His child, Flávio, who serves as a legislator, called for a assembly of his backers near the former president's residence to take place on Saturday evening.
Flávio Bolsonaro wrote on digital networks on Friday: Do you plan to struggle for your country, or watch it all from your mobile device there on your sofa? I urge you to struggle with us."
He said the vigil would be so backers could seek divine intervention for his well-being and for the restoration of democratic rule in our nation."
Embassy Asylum Concerns
Part of Justice Moraes's determination was the chance of Bolsonaro's move to foreign missions near the home, considering that the inquiries revealed a background of arranging to request asylum through a diplomatic representation", a statement said.
The court filing emphasizes that the American diplomatic mission in the capital, Brazil's capital, is located around 13km from Bolsonaro's home.
Worldwide Consequences
Bolsonaro's legal woes have provoked anger from fellow populist conservative US President President Trump, leading him to impose a half-rate duty on goods coming from Brazil.
He is being detained in a national police facility in the capital and will undergo a custody hearing on Sunday.
Latest Court Petitions
It was only on last Friday that the former president's lawyers asked the Supreme Court to allow him to fulfill his full incarceration period under home confinement, with digital surveillance.
They also requested that he be authorized to depart his residence for healthcare, saying he needed ongoing care for lung conditions and other illnesses.
Background on Conviction
Bolsonaro was convicted of orchestrating a conspiracy aimed at maintaining his control after he lost the 2022 election to his left-wing rival, Lula.
Supreme Court justices said that he was aware of a plan which included plans to kill his opponent and his VP candidate, Alckmin, and to arrest and execute Justice Moraes - the Supreme Court justice who has been overseeing Bolsonaro's trial.
The scheme was prevented because it couldn't obtain the backing of the army and air force commanders. The current president was took office without problem on the first day of 2023.
But a following week, on 8 January, many his followers invaded and destroyed government buildings in the federal district, Brasília.
The police took action and around approximately 1,500 persons were detained.
The magistrates found that the rioters had been provoked by the former president whose plan, they said, was for the country's army to step in, reestablish control and bring him back to power.
At the time, Bolsonaro's lawyers called the decades-long sentence unreasonably severe".
He was also banned from seeking elected position until 2060 - eight years after the end of his sentence.
The one-time head of state called the court case a political persecution and said it was aimed at blocking him participating in the 2026 national vote.
