Brazil's Supreme Court has put former President Jair Bolsonaro under house arrest ahead of his trial for an alleged coup plot, despite escalating tariffs and sanctions from US President Donald Trump.

Supreme Court Justice Alexandre de Moraes, the target of US Treasury sanctions last week, issued the arrest order against Bolsonaro.

His decision cited a failure to comply with restraining orders he had imposed on Bolsonaro for allegedly courting Trump's interference in the case.

Bolsonaro is on trial before the Supreme Court on charges he conspired with allies to violently overturn his 2022 electoral loss to leftist President Luiz Inacio Lula da Silva.

Trump has referred to the case as a "witch hunt" and called it grounds for a 50 percent tariff on Brazilian goods taking effect on Wednesday.

The US State Department condemned the house arrest order, saying Moraes was using Brazilian institutions to silence opposition and threaten democracy, adding the US would "hold accountable all those aiding and abetting sanctioned conduct."

It did not provide details, though Trump has said the US could still impose even higher tariffs on Brazilian imports.

The latest order from Moraes also banned Bolsonaro from using a cell phone or receiving visits, except for his lawyers and people authorised by the court.

A press representative for Bolsonaro confirmed he was placed under house arrest on Monday evening at his Brasilia residence by police who seized his cell phone.

Bolsonaro's lawyers said in a statement they would appeal the decision, arguing the former president had not violated any court order.

The former president's son, Senator Flavio Bolsonaro, told CNN Brasil that the order from Moraes was "a clear display of vengeance" for the US sanctions against the judge, adding: "I hope the Supreme Court can put the brakes on this person (Moraes) causing so much upheaval."

The judge's orders, including the restraining orders under penalty of arrest, have been upheld by the wider court.

Those orders and the larger case before the Supreme Court came after two years of investigations into Bolsonaro's role in an election-denying movement that culminated in riots by his supporters that rocked Brasilia in January 2023. (Reuters)