(Adds Supreme Court justice quotes)
LISBON/SAO PAULO, Feb 3 (Reuters) - Brazil's Supreme Court Justice Alexandre de Moraes confirmed on Friday that Senator Marcos do Val told him about an election conspiracy meeting he allegedly attended with former President Jair Bolsonaro and former lawmaker Daniel Silveira last year.
Do Val revealed on Thursday that Silveira, a close ally of Bolsonaro, tried to persuade him to join a conspiracy to overturn the far-right leader's electoral loss, asking him to try and get Moraes to make compromising comments in a taped conversation that could lead to the judge's arrest.
Bolsonaro had made baseless attacks on the integrity of Brazil's electronic voting system, which Moraes - also the head of the country's top electoral authority (TSE) - defended in decisions that the former president blamed for his defeat.
Moraes said during an event held in Lisbon that Do Val approached him to talk about the meeting. The justice said he then asked the senator to testify formalizing the allegations, but Do Val declined to do so.
"I asked the senator if he would reaffirm that and put it on paper, because then I would immediately take his testimony," Moraes said.
"But he told me it was an intelligence matter and that unfortunately he could not confirm it. So I just thanked him and said goodbye, because in my view what is not official does not exist".
Do Val told reporters on Thursday that Bolsonaro, narrowly defeated by President Luiz Inacio Lula da Silva in an October vote, "sat in silence" while Silveira laid out the plot against Moraes at the meeting.
Silveira was arrested by police on Thursday on a warrant issued by Moraes, who accused him of disobeying court rulings. Bolsonaro left Brazil for Florida 48 hours before Lula took office, without ever conceding defeat.
Bolsonaro is being investigated by Moraes at the Supreme Court for his alleged role in inflaming riots by his supporters, who stormed government buildings on Jan. 8 seeking to provoke a military coup. (Reporting by Catarina Demony in Lisbon, Gabriel Araujo and Eduardo Simoes in Sao Paulo; Editing by Steven Grattan and Chizu Nomiyama)