"This is a simulation of my image and my voice made with artificial intelligence. I am imprisoned and silenced by an unjust and arbitrary decision, based on something I never did. But I guarantee you one thing: no prison will silence the feeling of hope that we awakened," the AI-generated message said.

Israeli Prime Minister Benjamin Netanyahu also appeared in a recorded video congratulating Flavio Bolsonaro on his nomination.

"You are a great defender of Brazil . You are a great defender of the friendship between our peoples. And I know that you will lead Brazil to achieve ever greater accomplishments. Congratulations," Netanyahu said.

In his speech, Flavio Bolsonaro described the 2018 stabbing of his father, his imprisonment and the restrictions placed on him as three attempts to remove Jair Bolsonaro from political life. He accused opponents of "silencing the greatest leader of the right that this country has had" and pledged to "free Brazil" from what he called "the dirty hands of Lula and the Workers' Party."

He also said he leaves home each day wearing a bulletproof vest and accompanied by security , but that it would not stop him from running.

"With that purpose, today I assume, before God and before all of you, my Brazilian nation, the mission of being a candidate for the presidency of the Republic of Brazil of the future," he said.

Flavio Bolsonaro also called for constitutional changes, lower taxes and tougher criminal laws, including treating 14-year-olds convicted of rape as adults, longer prison terms for assaults on women and chemical castration for people convicted of raping children .

At a separate Workers' Party convention, President Luiz Inacio Lula da Silva said "this 80-year-old young man will win the elections again", signalling his intention to seek a fourth presidential term overall. Lula is currently serving his third, non-consecutive term.