John Francis Christopher Ducker (born 16 March 1943), known professionally as John Leeson, is an English actor, voice artist and freelance wine educator. He is known for portraying Bungle in Rainbow and voicing K9 in Doctor Who and spin-off The Sarah Jane Adventures. Early career Leeson trained at Royal Academy of Dramatic Art and his varied stage and television career spans half a century. It includes work in both repertory and West End productions including Neil Simon's Plaza Suite (1969), Flint (1970) and Don't Start Without Me (1971), and character acting work across a wide range of television sitcoms and costume dramas from the 1970s onwards, including Dad's Army, Sorry!, Rings on Their Fingers, adaptations of The Barretts of Wimpole Street and Vanity Fair, Shadow of the Noose, Crown Court and Longitude. He also embarked on a parallel career in voiceover work, freelancing as a continuity announcer with BFBS Television in Germany, BBC Television, and Channel 4. Doctor Who and spin-offs Leeson was first brought on as the voice of K9 in Doctor Who for 1977's The Invisible Enemy. Producer Graham Williams liked the character that the decision was made to retain him as a regular character to appeal to the younger members of the audience. Tom Baker, who played the Fourth Doctor, detested the character of K9, but gets on well with Leeson (when Leeson appeared on Tom Baker's edition of This Is Your Life in 2000, he entered on all fours). Leeson became worried about how appearing only as the voice of the character would hinder future employment if he was not appearing in visible roles; he left the programme after the conclusion of the 16th season in 1979. He was, however seen on-screen that season as the character Dugeen during the serial The Power of Kroll (1978–1979). David Brierly took over for four stories (one of which was never completed due to a BBC strike) the following year. When John Nathan-Turner took over as producer of the series for season 18 in 1980, Leeson agreed to return before the character was written out. Leeson also agreed to voice K9 in K-9 and Company (1981), a spin-off from Doctor Who which was not picked up after the airing of its pilot episode. He later voiced K9 for a cameo appearance in the 20th anniversary episode of Doctor Who, The Five Doctors, and has since reprised K9's voice in