A news outlet reported that jewels worth more than $3m were discovered in the backpack of a former aide in October 2021.

Justice Minister Flávio Dino announced the probe on Monday, calling on police to explore whether Bolsonaro’s staff tried to cross the border “without complying with legal procedures” for government gifts or high-value items.

The announcement follows a report in the O Estado de Sao Paulo newspaper that a former aide tried to bring $3.2m of jewellery into the country without declaring it, as a gift from the Saudi Arabian government to Bolsonaro and his wife Michelle.

Customs officials allegedly confiscated the jewellery from the backpack of a government staffer returning from Saudi Arabia in October 2021, while Bolsonaro was still in office. According to Friday’s newspaper report, the backpack contained a diamond necklace, a ring, a watch and earrings designed by Chopard, a luxury Swiss jeweller.

On Saturday, Bolsonaro denied any involvement in illegal activity. He told CNN Brazil he was being “crucified” for a gift he neither requested nor received.

A current cabinet member has called the incident an act of “smuggling”. In Brazil, any item brought into the country worth more than $1,000 is subject to taxes. Critics also say that, as a gift to the state, the jewellery should have been documented and surrendered to the government as part of the presidential collection.

The former aide had travelled to Riyadh with Bolsonaro’s Energy Minister Bento Albuquerque.

On Sunday, the Folha de S Paulo newspaper reported that another member of Albuquerque’s delegation carried a second package of Chopard jewellery gifted by Saudi Arabia, including a pen, cufflinks, a ring and a rosary. The paper states that this batch of luxury items was not discovered by authorities.

On Monday, Brazil’s Federal Revenue Service also announced that it would investigate whether the transport of the second package of jewellery violated customs laws.

The jewellery allegations add to a growing list of scandals and potential legal troubles faced by Bolsonaro, Brazil’s former far-right president.

Bolsonaro was narrowly defeated in his pursuit of a second term during an October 2022 run-off election, with the left-leaning Lula finishing ahead in the race.

In the lead-up to the vote, Bolsonaro spread false claims that Brazil’s voting system was rigged against him, raising alarm that he would not abide by the results of the election.

He has yet to concede defeat and left for the United States two days before the end of his term. In early January, his supporters stormed key government buildings in the Brazilian capital, calling for a military coup to remove Lula from power.

In Brazil, Bolsonaro currently faces investigations into whether he played a role in instigating the attack.