Career
John is a crime writer, who writes under the pen name Jonathan Gash. He is the author of the Lovejoy series of novels. He wrote the novel The Incomer under the pen name Graham Gaunt.
Grant is a doctor by training and worked as a general practitioner and pathologist.
He was head of bacteriology at the School of Hygiene and Tropical Medicine for the University of London between 1971 and 1988. He is also the author of a series of medical thrillers featuring the character Doctor Clare Burtonall.
Grant lives outside Colchester in Essex, the setting for many of his novels. He has also been published in Postscripts.