BRASILIA: Former Brazilian President Jair Bolsonaro and his wife Michelle chose to remain silent when they appeared before Federal Police on Thursday to testify in an investigation into jewelry gifts that they received from Arab heads of state and never declared.

They were called to testify at Police headquarters in Brasilia, along with Bolsonaro's former aide-de-camp Mauro Cid, his father, a retired army general, and another military officer that was a presidential aide.

To justify their silence, Bolsonaro's defense team argued that the case should be heard in Sao Paulo, where some of the jewelry was seized by customs agents at Guarulhos airport, and not in the jurisdiction of Brasilia.

The gifts of jewelry, expensive watches and gold-plated statuettes from Saudi Arabia and Bahrain were never declared and were only known about when Bolsonaro tried to recover the batch that was seized by customs, police investigations showed.

After the presidential gifts became a matter of public knowledge, a court ordered the couple to hand them over to the state. Bolsonaro aides and his lawyer then sought to buy back items that had been sold in the United States, the police said.

Prosecutors said the correct jurisdiction for the case is Brasilia, where the investigation was ordered by Supreme Court Justice Alexandre de Moraes.

It was the fifth time that Bolsonaro has been summoned by police to make depositions in a series of investigations, ranging from his attacks on Brazil's election system to his suspected role in inciting his supporters to storm government buildings to protest his election defeat.

The far-right Bolsonaro lost in October to leftist Luiz Inacio Lula da Silva, who took office on Jan. 1. His presidential offices, the Supreme Court and Congress were invaded and vandalized by Bolsonaro supporters one week later.

Bolsonaro and Michelle Bolsonaro spent the last two days preparing with their team of lawyers and advisers, officials in his political party said.

Both opted to remain silent, however, for fear that his former aide Cid, who has been in jail since May, could contradict their account and implicate the couple by seeking a plea bargain.

"Everyone is very worried about what could have come out if Cid confesses," said one party source with direct knowledge of the situation.

Cid, who handled the Bolsonaro finances, was arrested for his suspected involvement in a scheme to provide Bolsonaro with false vaccine cards during the COVID-19 pandemic.