The British foreign secretary, Dominic Raab, has been urged to block the appointment of Rwanda’s new high commissioner to London.

An American human rights group, the Lantos Foundation, says Johnston Busingye was involved in the detention of a prominent critic of the Rwandan government.

Paul Rusesabagina – who was portrayed in the film Hotel Rwanda – was tricked into returning to the country from exile last year and now faces terrorism charges.

Mr Busingye, until recently the justice minister, has admitted the government paid the person who carried out the deception.

The Rwandan government insists Mr Rusesabagina’s arrest complied with international law.