Lawyers for Brazil's ex-president Jair Bolsonaro have filed a new appeal requesting the annulment of his coup-plotting conviction, which saw him sentenced to 27 years in prison.

The defence is requesting "the annulment of the criminal process" and that Bolsonaro be acquitted, according to a document seen on Friday, three days after the Supreme Court ordered Bolsonaro to begin serving his prison term.

Bolsonaro was tried and convicted by a five-member section of the Supreme Court by a vote margin of four to one. Now his lawyers are appealing to the full 11-member court for it to throw out his trial, citing that lone, initial vote against conviction as grounds for the new appeal. An earlier appeal was already thrown out.

It was not immediately clear if this appeal can proceed with a chance of success. The smaller court section that convicted Bolsonaro and rejected an initial appeal said all avenues for such challenges had been exhausted.

Bolsonaro, the brash former army captain who fired up Brazil's right and reshaped the country's politics, is ending a divisive career jailed at a police headquarters in Brasilia.

The 70-year-old was convicted in September over a scheme to stop Luiz Inacio Lula da Silva from taking office as president after winning the 2022 elections. The plan included a plot to kill the veteran leftist.

Prosecutors said the scheme failed only due to a lack of support from military top brass.

Section number one of the Supreme Court rejected an appeal to his sentence early this month, and on Tuesday ruled the judgment was final.

Bolsonaro, who was president from 2019 to 2022, maintains that he is innocent and a victim of political persecution.

He has won support from US President Donald Trump, who has slammed a "witch hunt" of his ally and imposed sanctions and punitive tariffs on Brazil. Many of the tariffs have since been rolled back.

Bolsonaro had been under house arrest until last Saturday, when he was detained at police headquarters in the capital Brasilia for tampering with his ankle monitor using a soldering iron.

Supreme Court Justice Alexandre de Moraes said there were signs Bolsonaro was planning to flee during a planned vigil organized by his son outside his home.

The justice pointed to the location of the nearby US embassy, and Bolsonaro's close relationship with Trump, suggesting he may have tried to escape to seek political asylum.

Bolsonaro has since been detained in the police headquarters, in a room equipped with a TV, mini-fridge and air-conditioning. (AFP)