SAO PAULO (Reuters) - Brazil's authorities will not tolerate the dissemination of fake news in next year's elections, a Supreme Court justice said on Thursday after an electoral court acquitted far-right President Jair Bolsonaro of such a crime in the 2018 election.

       People found to be spreading fake news may face prison and any candidate involved could be banned from running, Supreme Court Justice Alexandre de Moraes said.

       Moraes, who will head the Superior Electoral Court (TSE) next year and took part in the Bolsonaro ruling, said "everyone knows" fake news was spread during the 2018 elections, but there was no definitive proof of wrongdoing.

       Moraes is also the Supreme Court justice in charge of sensitive investigations involving Bolsonaro and his allies. He said courts are better equipped today to handle cases involving false news dissemination.

       "We are not going to allow these digital militias to try again to destabilize the elections, the democratic institutions, backed by spurious and undeclared financing," Moraes said from the bench.

       (Reporting by Ricardo Brito; Writing by Ana Mano; Editing by Daniel Wallis)