He has appeared twice in Poirot (1989) opposite David Suchet. In the episode 'The King of Clubs', Sean played the brother of Niamh Cusack. Years later he played in 'Dead Man's Folly' the son of 'Sinead Cusack'.
Unlike his father, who was mostly known as a comic actor on stage, radio and in films, Pertwee took a different route into the profession and trained as a classical actor.