Brasília: Former far-right Brazilian president Jair Bolsonaro will remain under humanitarian house arrest in Brasilia as he serves a 27-year sentence for a failed coup attempt, the Supreme Court ruled Friday.

Bolsonaro, 71, was moved from prison to house arrest in March after being hospitalized with bronchopneumonia, for an initial period of 90 days.

Supreme Court Justice Alexandre de Moraes said that while Bolsonaro's health had improved, his age and other comorbidities meant that "the home environment is the most suitable for preserving his health."

"At the present moment, maintaining humanitarian house arrest is reasonable, appropriate and proportionate," he ruled, without setting a new deadline to review the decision.

Moraes did not punish Bolsonaro for the discovery of a pistol in his possession, but said the former president would no longer be allowed to have firearms at home and ordered the immediate seizure of any weapons.

According to the ruling, around 10 weapons -- a mix of pistols, rifles and shotguns -- were registered in Bolsonaro's name.

A member of Bolsonaro's security team was found with the pistol registered to the former president during a routine vehicle inspection last month.

Bolsonaro was sentenced to 27 years in prison last September for conspiring to remain in power despite his 2022 electoral defeat to leftist President Luiz Inacio Lula da Silva.

Brazil will have a presidential election in October in which Lula is seeking a fourth non-consecutive term in office.

His main rival is Bolsonaro's eldest son, the senator Flavio Bolsonaro. (AFP)