Sangster began his career as a clapper boy at the age of 16, before moving up to roles as an assistant director and screenwriter. But it was his stint as a writer at Britain's Hammer Horror studios which made his name, going on to tackle some of their most famous films, including The Mummy and Dracula, starring Sir Christopher Lee.
He later remarked, "All of a sudden I'm a cult figure. But it's all due to about five movies: a couple of Frankensteins, a couple of Draculas and a Mummy."
Sangster's other notable screen credits include Betty Davis' The Nanny and Paranoiac, which starred Oliver Reed.
He is survived by his second wife, actress Mary Peach, and his son. No cause of death had been made public as WENN went to press.