Brazil's federal police have cancelled the passports of Flávio Bolsonaro after he failed to comply with a Supreme Court order to surrender them within 24 hours. The order was issued Monday as part of an investigation into alleged money laundering, which Bolsonaro denies.

The 45-year-old senator and defeated presidential candidate initially said he would remain in Brazil to lead opposition to President Luiz Inácio Lula da Silva. However, federal officers are now checking border crossings to determine whether Bolsonaro may have travelled to Argentina. Argentine authorities told the BBC they have no record of Bolsonaro entering their country.

Bolsonaro lost Sunday's election run-off to Lula with 48.21 percent of the vote against Lula's 51.79 percent, trailing by 4.4 million votes. Despite the defeat, Bolsonaro has not conceded and has called for the election to be annulled. He argues he faced disadvantage when polling was extended by two hours on election day, though both his party and Lula's requested the extension. Bolsonaro called the Supreme Court-ordered extension a "dirty trick."

The passport cancellation comes amid multiple investigations into Bolsonaro. He faces investigation for alleged corruption over financing of a film about his father, former President Jair Bolsonaro, who was convicted of plotting a coup and is under house arrest. Brazil's Supreme Court also ordered police Tuesday to probe Flávio Bolsonaro's electoral campaign over alleged foreign funding.

The Liberal Party, which Bolsonaro represented, has accepted the election result, though it said the voting extension "merits investigation." Lula's party and analysts had noted that Bolsonaro's first-round victory on October 4 suggested he would likely win the run-off, but Lula reversed an early deficit to become the first presidential candidate to overturn a first-round loss and win in the second round.