Benin opposition leader and former justice minister Reckya Madougou was sentenced on Saturday to 20 years in prison for terrorism before a special court in the capital Porto-Novo.

After more than 20 hours of hearings, Madougou, 47, was found guilty of "complicity in terrorist acts" by the Economic Crime and Terrorism Court, or Criet, which on Tuesday sentenced another key opposition figure to 10 years.

Critics say the court, set up in 2016, has been used by President Patrice Talon's regime to crack down on the opposition and pushed Benin into authoritarianism.

"This court has deliberately decided to penalise an innocent person," Madougou said shortly before her prison sentence was announced.

"I have never been and I will never be a terrorist."

"It's a sad day for our justice system, I maintain that there is no proof," one of her lawyers, Robert Dossou, told AFP.

Madougou was one of several Benin opposition leaders banned from running in an election in April in which Talon won a second term with 86 percent of the vote.

She was arrested in March -- just weeks before the election -- accused of financing an operation to assassinate political figures to prevent the vote, in an alleged bid to "destabilise" the country.

One of her France-based lawyers Antoine Vey told the trial on Friday that "this procedure is nothing but a political attack".

"Even before her arrest, everything was orchestrated," Vey said a day after arriving from Paris. He asked for the trial to be cancelled, before leaving the court and never returning.

He then told AFP that it was "a trial in which nothing was judicial".

Benin was long praised for its thriving multi-party democracy in a troubled region. But critics say the West African state's democracy has steadily eroded under Talon, a 63-year-old cotton magnate first elected in 2016.

Some opposition leaders have fled the country while others were disqualified from running in elections, or targeted for investigation.

Joel Aivo, a professor who had been held for eight months, was found guilty on Tuesday of plotting against the state and money laundering.

Aivo, who was also barred from running in the election, was arrested on April 15, four days after the ballot that saw Talon returned to power.

AFP