Former Brazilian far-right president Jair Bolsonaro appeared before federal police on Wednesday to testify over anti-government riots by his supporters on January 8, a police source told AFP.

Bolsonaro is being investigated for his alleged role in masterminding and instigating the riots that sought the overthrow of his successor, President Luiz Inacio Lula da Silva.

Bolsonaro, who returned to Brazil in late March after spending three months in Florida, has always denied his involvement in the riots.

Bolsonaro arrived at the federal police headquarters in Brasilia in a vehicle with tinted windows and made no statement to the press.

Lula, who previously led Brazil from 2003 to 2010, narrowly beat Bolsonaro in a brutal, divisive election last October.

Thousands of Bolsonaro's supporters barged into Congress, the Supreme Court and the presidential palace in Brasilia in January, a week after Lula took office.

In scenes reminiscent of the January 6, 2021 riots in Washington by supporters of ex-president Donald Trump -- Bolsonaro's political role model -- they trashed offices, smashed windows, vandalized artworks and called for the military to intervene to oust Lula.

Some 1,800 people have been arrested.