Frank Windsor played Ranulf Fitzwilliam in the Doctor Who serial The King's Demons and Inspector Mackenzie in Ghost Light.
He is best known for playing Det. Chief Supt./Det. Chief Insp/Det. Sgt. John Watt in police dramas Softly, Softly, Softly, Softly: Taskforce, Z-Cars, Jack the Ripper and Second Verdict.