One of the Rwandan president’s former bodyguards, Joel Mutabazi, is refusing to be tried for alleged terrorism.
He told the court he has no faith in Rwanda’s justice and that he had been illegally extradited from Uganda.
Mr Mutabazi and 15 others are accused of plotting attacks and could face life sentences. Most deny the charges.
Meanwhile, UN special rapporteur Maina Kiai told the BBC that most politicians who are openly critical of the government end up in legal trouble.
Paul Kagame’s government has denied persecuting its opponents.
But earlier this year, following the apparent murder of a prominent dissident in South Africa, he warned. “There are consequences for betraying your country.”