Donat

 was one of Citizen Maximilien Robespierre to investigate the Scarlet Pimpernel, first when the Sixth Doctor posed as the Scarlet Pimpernel. He later interrogated Frederic. He managed to track the Pimpernel to the house that Peri Brown and Percy Blakeney lived at. Following Blakeney to his home world he tried to kill him but didn't manage it fully. (AUDIO: Plight of the Pimpernel)