John Leeson

John Francis Christopher Ducker (16 March 1943 – 1 November 2026), known professionally as John Leeson, was an English actor. He was known for portraying Bungle in Rainbow and voicing K9 in Doctor Who and spin-offs The Sarah Jane Adventures and K9. Leeson trained at the Royal Academy of Dramatic Art and had several theatre and television roles before his work in Doctor Who. Initially planned for one serial, K9 appeared in several seasons of Doctor Who's original run before returning in 2006, which led to further appearances in other media.

John Francis Christopher Ducker was born at St Francis Hospital in Stoneygate, Leicester, England, on 16 March 1943, the third child of Barbara Mary Gilbert (née Payne; d. 1982) and Eric Neilson Ducker (d. 1976). His older siblings were Alison and Peter. His father was the vicar of St Margaret's Church in Leicester, himself the son of a vicar from Derbyshire. Ducker's maternal grandfather, Canon Payne, worked with the Red Cross during the First World War and received an OBE. Ducker's first job was as a hospital porter at the Leicester Royal Infirmary, at which his father was a hospital chaplain.

Following childhood experiences at Leicester's Little Theatre and productions at the St Margaret's Drama Society (of which his mother was president), Ducker successfully auditioned for the Royal Academy of Dramatic Art (RADA), which he attended from 1962 to 1964. He adopted a stage name, John Leeson, based on his godmother's surname. Leeson attended RADA with Terry Hands and Susan Fleetwood, and during his time travelled to the United States to perform plays by William Shakespeare. His first role was repertory theatre at Frinton-on-Sea, directed by one of his RADA tutors, Michael Ashton. He later worked in Colchester, Birmingham, Newcastle, and at Nottingham Playhouse, predominantly playing character roles like old men; he enjoyed wearing makeup and disguises.

Kenneth Waller introduced Leeson to some London production companies; his first London stage show was held by Moral Re-Armament at Westminster Theatre, while his introduction to West End theatre was Plaza Suite at the Lyric Theatre in 1969. He was soon introduced to television acting as a French hippie in Crossroads (1967–1968). Leeson became a regular television performer, including in the Dad's Army episode "Sons of the Sea" (1969), 50 episodes of Rainbow (1972), and Sorry! (1981). He continued theatre work, including in Don't Start Without Me at the Garrick Theatre in 1971.

One of Leeson's friends, director Derrick Goodwin, cast him as the voice of K9 in the Doctor Who serial The Invisible Enemy (1977) after a chance encounter at the Duke of Kent pub. Producer Graham Williams encouraged him to audition for the role, seeking a more humorous tone for the programme. Williams and script editor Robert Holmes liked the character so much that the decision was made to retain him as a regular character to appeal to the younger members of the audience. The character initially had little involvement in serials due to his last-minute addition, but became more involved in The Sun Makers (1977) and Underworld (1978). K9 could not appear in The Power of Kroll (1978–1979) due to the filming location; Leeson, who was under contract, appeared in person as the technician Dugeen. Tom Baker, who played the Fourth Doctor, detested the character of K9, but had a good friendship with Leeson.

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 departed in The Armageddon Factor (1979), at the end of the sixteenth season, replaced by David Brierley. After Brierley's departure, Leeson returned for the eighteenth season (1980–1981) at the request of producer John Nathan-Turner, as the character was being written out of the series; Nathan-Turner felt Brierley "lacked the sparkle" of Leeson's performance. He voiced the character in K-9 and Company (1981), a failed television pilot starring Elisabeth Sladen as Sarah Jane Smith. He later had cameo appearances in "The Five Doctors" (1983) and Dimensions in Time (1993).

Leeson's vocal contributions to Doctor Who can also be heard as other characters in the serials The Invisible Enemy and Remembrance of the Daleks. He voiced the character for several appearances outside of Doctor Who, including Blue Peter (1977), The Generation Game (1981), The Weakest Link (2007), Celebrity Eggheads (2010), and Pointless Celebrities (2013). Leeson portrayed Anthony in the Doctor Who spin-off film Downtime (1995) and returned as K9 in Audio Adventures in Time and Space before appearing in several audio dramas by Big Finish Productions.

He returned to Doctor Who in the 2006 episode "School Reunion" alongside Sladen, which led to frequent appearances in the spinoff series The Sarah Jane Adventures (2007–2011). Around the same time, he appeared in another spinoff series, K9 (2009–2010); Leeson found the series "strange", feeling that K9 works best as a side character instead of the leading role. In November 2013, Leeson appeared as K9 in the one-off 50th anniversary comedy homage The Five(ish) Doctors Reboot. K9's producers were set to create a feature film, Timequake, for the character's fortieth anniversary in 2017, starring Leeson.

Leeson appeared in two episodes of Blake's 7: "Mission to Destiny" (1978) and "Gambit" (1979). Other credits include appearances Jigsaw in which he voiced Jigg, the show's "mascot". He was one of the resident team of actors in stunts for ITV's Game for a Laugh (1981–1985), and he portrayed several different characters in Beadle's About (1986–1987, 1992).

His film credits included the Hunt Secretary in the film of Tarka the Otter (1979) and a professor in Miami Connection (1985). Leeson worked as a continuity announcer for several networks, including BFBS Television, the BBC, and Channel 4, and he read extensively for the Calibre Audio Library. He narrated and provided voices for The Space Gypsy Adventures on Children's UK hospital radio. In 2026, Leeson reunited with Tom Baker in the Kickstarter-funded audio drama series Sir Sherlock, playing Dr. Watson to Baker's Sherlock Holmes.

Under his birth name, he was an accredited tutor for the Wine & Spirit Education Trust, and he was a member both of the Association of Wine Educators and the Circle of Wine Writers. He was a freelance lecturer in wine both on land and in cruises at sea, and was a regular tutor for The Wine Education Service Ltd. He contributed a chapter on teaching wine tasting (in his birth name of John Ducker) to Educated Tastes: Food, Drink and Connoisseur Culture, edited by Jeremy Strong.

Leeson's autobiography, entitled Flight of the Budgerigar, was published by Hirst in October 2011. It was superseded by an updated and expanded version entitled Tweaking the Tail which was published in July 2013 by Fantom Films. A book of favourite recipes collected across the years, Dog's Dinners, also published by Fantom, was published in May 2014.

Leeson married Judy Griffiths in Kensington, on 2 August 1969. Judy worked as an assistant at the BBC, including on Blue Peter. Leeson was acting as a bridegroom in Private Suite at the time of his wedding; he performed the show twice in the same evening hours after his wedding. Their son, Guy Ducker (born 1972), is a film editor and director.

Leeson died on 1 November 2026, aged 83, after a period of illness. His death was announced by his son, Guy. Former Doctor Who showrunner Russell T Davies paid tribute to Leeson, praising his voice as K9: "pitched perfectly so that kids could impersonate him. That's not easy, that's hell of a piece of acting".

Leeson served as a local justice of the peace for over 25 years. In 2002 and 2010, under his birth name of John Ducker, he stood as a candidate for the Liberal Democrats in the district of Perivale in the local council elections for Ealing London Borough Council, but failed to be elected.