John Leeson

John Francis Christian Ducker (born in March 1943 ) better known by his stage name John Leeson, voiced K9 from 1977-1979 and again from 1980-2010 on Doctor Who, K9 and Company, The Sarah Jane Adventures and K9.

He also voiced the Nucleus in the Doctor Who television story The Invisible Enemy, played Dugeen in the Doctor Who television story The Power of Kroll, voiced the Dalek battle computer in the Doctor Who television story Remembrance of the Daleks and played Anthony in the Reeltime Pictures spin-off video Downtime. He also provided the uncredited voice of the computer in the Doctor Who television story The Sun Makers.

On audio, he reprised K9 for two Adventures in a Pocket Universe audio dramas by BBV Productions and in Big Finish Productions' Doctor Who and Gallifrey audio series and reprised the Nucleus in the Big Finish Doctor Who audio story Revenge of the Swarm. He also voiced Chief Mover in Magic Bullet Productions' Storm Mine, Machina in The Paradox Planet and Legacy of Death and the fifth incarnation of Drax in The Trouble with Drax.

Tom Baker detested the character of K9, but got on very well with Leeson. A favourite joke during filming breaks was for Baker to work out crossword puzzles, asking the K9 prop the clues with Leeson giving the answers in character. The short sketch Merry Christmas Doctor Who involved K9 telling the Fourth Doctor and Romana I that for Christmas he would like "enough ball bearings to last the series through and fewer sill irons on the floors of the planets we visit," as well as the robot dog downing some gin before beginning a drunken rendition of "We Wish You a Merry Christmas". When Leeson appeared on Tom Baker's edition of in 2000, Leeson entered on all fours.

Leeson himself became frustrated with the character. He left the programme after the conclusion of the 16th season in 1978. David Brierley 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 series producer for season 18 in 1980, he tempted Leeson back, with the promise the character would be "killed off" that year. Although the character was, eventually, not killed off, merely written out, Leeson agreed to return, and portrayed all of K9's subsequent return appearances on Doctor Who and its spin-off shows.

Other credits include appearances in Blake's 7 (the Season A episode "Mission to Destiny" and the Season B episode "Gambit"), in which he played the giant Biggum, who was so tall only his feet were seen and his voice heard,,  and Bungle in the children's television series. Leeson is also the voice behind the characters on Children's UK.

Today, he is now most likely to be heard as continuity announcer on Channel 4 in Britain. He also contributed to the charity reference book Behind the Sofa: Celebrity Memories of Doctor Who.

Doctor Who

 * The Invisible Enemy (also as the Nucleus)
 * The Sun Makers (also as the Computer)
 * Underworld
 * The Invasion of Time
 * The Ribos Operation
 * The Pirate Planet
 * The Stones of Blood
 * The Androids of Tara
 * The Power of Kroll as Dugeen
 * The Armageddon Factor
 * The Leisure Hive
 * Meglos
 * Full Circle
 * State of Decay
 * Warriors' Gate
 * The Five Doctors
 * Remembrance of the Daleks as Dalek Battle Computer
 * School Reunion
 * Journey's End

Mini-episodes

 * Dimensions in Time

K9 and Company

 * A Girl's Best Friend

The Sarah Jane Adventures

 * Invasion of the Bane
 * The Lost Boy
 * The Mad Woman in the Attic
 * The Wedding of Sarah Jane Smith
 * Mona Lisa's Revenge
 * The Gift
 * The Nightmare Man
 * Goodbye, Sarah Jane Smith

Mini-episodes

 * From Raxacoricofallapatorius With Love

K9

 * Regeneration
 * Liberation
 * The Korven
 * The Bounty Hunter
 * Sirens of Ceres
 * Fear Itself
 * The Fall of the House of Gryffen
 * Jaws of Orthrus
 * Dream-Eaters
 * Curse of Anubis
 * Oroborus
 * Alien Avatar
 * Aeolian
 * The Last Oak Tree
 * Black Hunger
 * The Cambridge Spy
 * Lost Library of Ukko
 * Mutant Copper
 * The Custodians
 * Taphony and the Time Loop
 * Robot Gladiators
 * Mind Snap
 * Angel of the North
 * The Last Precinct
 * Hound of the Korven
 * The Eclipse of the Korven

Direct-to-video

 * Downtime as Anthony

Webcasts

 * Shada

Video games

 * LEGO Dimensions

Adventures in a Pocket Universe

 * The Choice
 * The Search

Big Finish Doctor Who audio stories

 * Zagreus
 * Shada
 * The Time Vampire
 * The Sands of Life
 * Phantoms of the Deep
 * The Dalek Contract / The Final Phase
 * Revenge of the Swarm as the Nucleus/Computer
 * The Romance of Crime
 * The English Way of Death
 * The Exxilons
 * Requiem for the Rocket Men
 * The Well-Mannered War
 * Death Match
 * The Fate of Krelos / Return to Telos
 * Wave of Destruction
 * The Paradox Planet / Legacy of Death (also as Machina)
 * The Trouble with Drax (also as the fifth Drax)
 * The Pursuit of History / Casualties of Time
 * The Beast of Kravenos
 * The Eternal Battle
 * The Silent Scream
 * The Mind Runners / The Demon Rises

Gallifrey

 * Weapon of Choice
 * Square One
 * The Inquiry
 * A Blind Eye
 * Lies
 * Pandora
 * Insurgency
 * Imperiatrix
 * Fractures
 * Warfare
 * Appropriation
 * Mindbomb
 * Panacea
 * Reborn
 * Disassembled
 * Annihilation
 * Forever
 * Arbitration
 * Ascension

Kaldor City

 * Storm Mine as Chief Mover

Audiobooks

 * Doctor Who and the Ribos Operation
 * The Stones of Blood (K9 voice)
 * Peculiar Lives
 * Shada (K9 voice)
 * The Androids of Tara
 * The Adventures of K9
 * Full Circle (K9 voice)
 * K9 and Company
 * Doctor Who and the State of Decay
 * Doctor Who and the Invasion of Time
 * Doctor Who and the Invisible Enemy

Documentary

 * Where on Earth Is... Katy Manning Because She'd Really Like to Know!
 * K9 Unleashed
 * A New Beginning
 * Friends Reunited
 * Parrot Fashion
 * Getting Blood from the Stones
 * A Matter of Time
 * Celebration
 * Dreams and Fantasy
 * Out of Time
 * The Vampire Lovers
 * The Dreaming
 * All Aboard the Starliner
 * The Doctors Revisited - The Fourth Doctor
 * Doctor Who Live: The Afterparty
 * Toby Hadoke's Who's Round

Other

 * Blue Peter 1977 & 2006
 * Myth Runner
 * The Weakest Link: Doctor Who Special
 * My Life: I Am Ethan
 * Pointless Celebrities: Doctor Who Special
 * The Five(ish) Doctors Reboot
 * K9's Question Time