SAO PAULO, Brazil: A judge of Brazil's top electoral court ruled on October 15 that Meta must immediately adopt measures to ensure equal treatment of the two presidential candidates ahead of an October 25 runoff.

The ruling comes shortly after President Luiz Inácio Lula da Silva, who is running against Flávio Bolsonaro, filed a complaint accusing the tech company that owns Instagram, Facebook and WhatsApp of using biased algorithms and AI restrictions to favor the opposition candidate ahead of the election.

Justice Marco Aurélio Bellizze ruled that Meta cannot reduce the distribution of political content, restrict searches, or remove posts in a way that creates an imbalance between Lula and Bolsonaro. His ruling also orders the company to ensure its artificial intelligence tool applies identical criteria to both candidacies.

Bellizze said in his ruling that Meta must pay a fine of 500,000 reais (US$98,000) per day if it fails to comply.

The legal filing said Meta has subjected Lula's campaign materials and organic posts to "unjustified reductions in reach." It also said Meta has not complied with a plan submitted to the electoral court to address these issues.

Meta declined to comment on the ruling.

Lula's campaign argued that accounts and advertisements associated with Flávio Bolsonaro have reportedly received artificially inflated visibility, with engagement metrics rivaling global celebrities. The two are in a close race for the presidency, after the son of former President Jair Bolsonaro garnered 47 percent of the vote against 45 percent of the incumbent in the first round on October 4.

Lula's complaint also claimed a stark disparity in Meta's artificial intelligence tools, with users unable to generate campaign images related to the 80-year-old president via WhatsApp's "Meta AI" feature, but able to do so if they want to promote content supporting Flávio Bolsonaro.

Gean Ferreira and Evelyn Santos, both lawyers for the Lula campaign, said in a statement that Meta's content delivery is selective against the incumbent and favorable to Bolsonaro, an ally of U.S. President Donald Trump.

"On one hand, content from candidate Luiz Inácio Lula da Silva and his supporters faces delivery restrictions, without any justification or transparency," the lawyers said. "On the other hand, profiles acting as political operatives for the opposing side ... receive a disproportionate and artificial reach, garnering more views even than global celebrities."

Lula's campaign wanted Brazil's top electoral court to order an immediate end to the content restrictions and pressure Meta to make up for the lost traction by doubling its reach to rectify the harm inflicted.

On October 11, as Lula's voters began complaining about their use of Meta tools, the big tech company told the electoral court it rejects accusations that it is skewed toward Bolsonaro. The company admitted it has faced technical glitches that affect accounts beyond Brazil. It also said it complies fully with Brazil's electoral regulations and is committed to providing equal platform access for all political parties.