According to "The Daily Telegraph", BBC News and "The Times", Madoc is especially remembered for his role in "The Deadly Attachment", an episode of the comedy "Dad's Army" in which he played a U-boat captain held prisoner by the Walmington-on-Sea platoon of the Home Guard. He records names on his "list" for the day of reckoning after the war is won, prompting Captain Mainwaring's famous line "Don't tell him, Pike!" Madoc also played a German villain in the TV series "Fortunes of War", directed by James Cellan Jones.