A US lawyer has been arrested on allegations of genocide denial, days after arriving in Rwanda, the nation's police force has said.
Peter Erlinder had arrived to help defend opposition leader Victoire Ingabire Umuhoza, who was charged with promoting genocide ideology last month.
Police spokesman Eric Kayiranga said Mr Erlinder was arrested on Friday morning and would face charges in court.
Rwanda's 1994 genocide claimed the lives of 800,000 people, mostly Tutsis.
Ms Ingabire, an ethnic Hutu, was arrested for allegedly propagating genocide ideology after she called for action to be taken against those responsible for killing Hutus during the 1994 conflict.
She was freed on bail but her passport was seized and she was banned from leaving the capital, Kigali. She could be sentenced to more than two decades in prison if convicted.
Mr Erlinder is the lead defence counsel for top genocide suspects at the International Criminal Tribunal for Rwanda in Arusha, Tanzania.
He had been planning to help Ms Ingabire's defence team but chief prosecutor Martin Ngoga said he had been arrested for remarks made in publications and statements.
US Assistant Secretary of State for African Affairs Johnnie Carson has accused the Kigali government of restricting freedom ahead of the 9 August presidential election, in which Ms Ingabire was a challenger.
President Paul Kagame is a Tutsi former rebel leader who came to power to end the killings. His forces have been accused of massacring Hutus after the genocide ended.
Ms Ingabire, who leads the Unified Democratic Forces party, has previously said she had been harassed since returning from exile in January.