A court in Gabon has sentenced the former first lady and the son of deposed President Ali Bongo to 20 years in jail following a two-day trial.

On Tuesday night, Sylvia Bongo and Noureddin Bongo were found guilty of embezzlement and corruption after a trial that began a day earlier. They were not present.

They were both fined 100m CFA francs ($177,000; £135,000), with Noureddin ordered to pay an extra 1.2tn CFA francs ($2.1; £1.6bn) for financial damages suffered by the Gabonese state.

They were accused of exploiting Ali Bongo’s condition after he suffered a stroke in 2018 to run Gabon for their own personal profit. They denied the charges ahead of their trial, describing it as “a legal farce.”

Ali Bongo was ousted in an August 2023 coup led by Brice Oligui Nguema, who has since shed his military uniform and was elected president earlier this year.

Following the military takeover, Bongo’s wife and son were detained in Gabon for 20 months before being released in May and permitted to leave the country for London on medical grounds.

The former president is not facing prosecution and was also released from house arrest, where he had reportedly remained, although Gabonese authorities said he was free to move about as he wished.

Separately, a money laundering investigation is underway in Switzerland against Sylvia Bongo, the public prosecutor’s office in the country has told the BBC.

Gabonese state prosecutor Eddy Minang on Monday told the court that they were “surprised” not to see the former first lady and her son in court as the trial began.

Noureddin described the conviction as a “rubber-stamping exercise”, saying it had been “predetermined in [Oligui Nguema’s office] a long time ago”.

He said it was “disappointing that a finding of guilt has been made without any semblance of evidence”.

Their conviction comes as a surprise for the unusual swift handling of the case, which they have alleged to be politically motivated. The trial had been expected to last until Friday.

The trial of the other accused will continue. Nine co-accused, former allies of the Bongos, were present in court at the start of the trial, according to reports.

Sylvia Bongo was born in France and holds French nationality, as does her son.

They have claimed they were tortured by the military during their detention in Gabon and filed a case in France last year. Gabonese authorities have denied the allegations.

Noureddin was ordered to pay the extra $2.1bn fine due to his role as the General Coordinator of Presidential Affairs, a position that he allegedly used to embezzle this amount of public money.

He was also accused of forgery as he reportedly had the president’s signature and seal, which were allegedly used to siphon funds from the state. He denies all the charges.

The Bongo family ruled Gabon for more than five decades. Ali Bongo was in power for 14 years before he was ousted. He had succeeded his father, Omar Bongo, who had ruled for 42 years.

Over the years, the family has been accused of amassing wealth for themselves at the expense of the country – allegations they deny.

Despite being an oil-rich nation, about a third of Gabon’s population lives below the poverty line, according to the UN.