Bolsonaro has been taken into custody after authorities found he posed a concrete flight risk while under home confinement.
The ex-president was convicted of plotting a government overthrow in last fall and given more than a 27-year term in prison, but he remained under house arrest pending legal challenges.
Brazilian Supreme Court Justice the presiding justice said the action to imprison the elderly politician was a precautionary step after "new facts" came to light.
This involved attempting to break his electronic bracelet and a call for a demonstration that could "allow for a chance to flee".
Legal Document Reveals Flight Fears
In a filing authorising the custody, the magistrate said data from the unit overseeing the former president's confinement suggested the ex-president's "intention to break the electronic ankle bracelet to ensure success in his flight.
This, it said, would be "facilitated by the confusion caused by the protest called by his offspring.
His son, his son Flávio, who holds office as a legislator, called for a assembly of his backers near the former president's residence to take place on Saturday evening.
The senator wrote on digital networks on the previous day: Will you battle for your country, or watch it all from your smartphone there on your settee? I invite you to fight with us."
He said the vigil would be so backers could "pray for his physical condition and for the reestablishment of democratic governance in our land."
Embassy Asylum Concerns
Part of the magistrate's ruling was the possibility of Bolsonaro's transfer to diplomatic missions near the residence, considering that the investigations revealed a background of arranging to request asylum through a diplomatic representation", a statement said.
The legal document emphasizes that the American diplomatic mission in the capital, Brasilia, is positioned around 13km from the former president's residence.
International Reactions
His judicial problems have generated frustration from fellow right-wing populist United States President Trump, leading him to impose a half-rate duty on goods coming from Brazil.
Bolsonaro is being kept in a federal law enforcement building in Brasilia and will experience a custody hearing on Sunday.
Recent Legal Requests
It was only on Friday that the ex-leader's attorneys asked the High Court to permit him to fulfill his full incarceration period under house arrest, with tracking devices.
They also asked that Bolsonaro be allowed to depart his residence for medical care, saying he needed frequent medical attention for pulmonary infections and other health problems.
Details of Guilty Verdict
The former president was determined responsible of leading a scheme aimed at maintaining his control after he was defeated in the 2022 election to his ideological adversary, President Lula.
Top judicial officials said that he was aware of a plan which involved plans to kill his opponent and his VP candidate, Alckmin, and to imprison and murder Alexandre de Moraes - the Supreme Court justice who has been managing Bolsonaro's trial.
The scheme was prevented because it failed to get the support of the armed forces officials. The current president was sworn in without incident on the first day of 2023.
But a seven days after, on 8 January, many his backers invaded and destroyed official structures in the national capital, the capital city.
The police took action and around 1,500 people were detained.
The justices found that the rioters had been provoked by the former president whose scheme, they said, was for the national armed forces to take action, bring back stability and bring him back to power.
At the moment, his attorneys called the over 27-year sentence extremely harsh.
He was also banned from running for public office until the year 2060 - eight years after the completion of his term.
The ex-leader called the legal proceedings a "witch hunt and said it was intended to stop him participating in the 2026 national vote.
