Paul Rusesabagina, the "Hotel Rwanda" hero who became a fierce government critic, was found guilty on Monday on terror charges after what his supporters say was a politically motivated show trial.
He was convicted of backing a rebel group blamed for deadly gun, grenade and arson attacks in Rwanda in 2018 and 2019.
"He founded a terrorist organisation that attacked Rwanda, he financially contributed to terrorist activities," Justice Beatrice Mukamurenzi said at the end of a seven-month trial.
Rwandan prosecutors have sought a life sentence for Rusesabagina, the 67-year-old former hotelier credited with saving hundreds of lives during the 1994 Genocide against the Tutsi, and whose actions inspired the Hollywood film.
Neither he nor his lawyers were in court for the verdict, although the 20 other defendants in the case attended.
Rusesabagina was arrested in August 2020 when a plane he believed was bound for Burundi landed instead in the Rwandan capital Kigali.
His family says Rusesabagina was kidnapped and had rejected the nine charges against him as payback by a vengeful government for his outspoken views.
Earlier this month, President Paul Kagame had dismissed criticism of the case, saying Rusesabagina was in the dock over the lives lost "because of his actions".
The trial began in February but the Belgian citizen and US green card holder boycotted it starting in March, accusing the court of "unfairness and a lack of independence".
The United States -- which awarded Rusesabagina its Presidential Medal of Freedom in 2005 -- along with the European Parliament and Belgium were among those to raise concerns about his transfer to Rwanda and the fairness of his trial.
Rusesabagina was the former manager of the Hotel des Mille Collines in Kigali, where he sheltered hundreds of guests during the Genocide against the Tutsi.
A decade later, the American actor Don Cheadle played Rusesabagina in the Oscar-nominated blockbuster that brought his story to an international audience.
Rusesabagina soon became disillusioned with the new government led by Kagame. He left Rwanda in 1996, living in Belgium and then the United States.
Abroad, he developed close ties with opposition groups in exile.
Kagame's government accused Rusesabagina of supporting the National Liberation Front (FLN), a rebel group blamed for the attacks in 2018 and 2019 that killed nine people.
Rusesabagina denied any involvement in the attacks, but was a founder of the Rwandan Movement for Democratic Change (MRCD), an opposition group of which the FLN is seen as the armed wing.
"MRCD-FLN committed terror acts. MRCD cannot be separated from military acts" of FLN, said the judge, Mukamurenzi.
Prosecutors in June said Rusesabagina "encouraged and empowered the fighters to commit those terrorist acts".
But his co-defendants gave conflicting testimony about the level of Rusesabagina's involvement with the FLN and its fighters.
His family, who have campaigned globally for his release, say Rusesabagina is a political prisoner and accuse the Rwandan authorities of torturing him in custody.
The Hotel Rwanda Foundation, which supports Rusesabagina, said in a statement earlier this month it was a "show trial" and that the government had failed to provide any credible evidence against him.