Robert Banks Stewart, creator of the Zygons and the Krynoids for Doctor Who, has died at the age of 84.

A prolific writer, he worked on Danger Man, Adam Adamant Lives! and The Avengers in the 1960s alongside episodes of Undermind, as well as many spy and detective series in later years including Jason King, The Protectors, Callan and The Sweeney. He was the creator of both Shoestring and Bergerac.

His first novel was published when he was 81, and an autobiographical memoir was published last year by Miwk Publishing. A tribute by publisher Matt West can be read here