Prior to joining the BBC, Whitaker worked as a writer, actor and director with the York Repertory Group. A play he wrote for them, ‘A Choice of Partners’, gained the attention of the BBC's script department. They commissioned Whitaker to work on the programmes Garry Halliday and the long-running Compact. Whitaker also contributed his own scripts for a number of Doctor Who serials, including The Crusade, The Power of the Daleks, The Evil of the Daleks, The Enemy of the World and The Wheel in Space. Although he left the post of story editor in 1964 his final script for the show was The Ambassadors of Death. He had not planned to stay longer than a year as Doctor Who's story editor, as he thought the serial might not be renewed. He had therefore agreed to take up a role working on another production. His other work included writing the Dalekcomic strip for the weekly children's magazine TV Century 21, in addition to the stage playThe Curse of the Daleks. In 1964, Whitaker published the first novelisation of a Doctor Who serial; more than 150 other such books would be published in the course of the next 30 years. His own, Doctor Who in an Exciting Adventure with the Daleks, was based on Terry Nation's script for the first Dalek TV serial. He completed a second novelisation the following year, this time based on his own script for The Crusade. Both books were originally published by Frederick Muller, with the first also being given a paperback release by Armada. In 1973, Whitaker's novelisations were re-issued by Target Books as part of its launch of a new series of novelisations; Whitaker's Dalek story was re-titled Doctor Who and the Daleks. From 1966 to 1968 Whitaker was the chairman of the Writers Guild of Great Britain. He moved to Australia in the 70's and contributed to the series "Homicide", "The Drifter" and "Elephant Boy" before returning to the UK. Before his death in 1980, Whitaker had been undergoing treatment for cancer. He died leaving his novelisation of The Enemy of the World unfinished and his plans to adapt The Evil of the Daleks unrealised. The adaptation of The Enemy of the World was ultimately written by Ian Marter without using any of the material prepared by Whitaker, while The Evil of the Daleks was eventually novelised by John Peel and published in 1993.
Although tasked with writing the serial that would later be produced as The Invasion, Whitaker was ultimately unable to contribute a script, leaving then-story editor and future Doctor Who producer Derrick Sherwin to write it himself.
