Best-selling author Lynda La Plante has begun writing Tennison, a prequel to Prime Suspect, which she will also adapt for television.
La Plante said: "I am extremely excited to have begun work on the Tennison project. Jane Tennison is a character who millions of people know and admire from my books and TV series, Prime Suspect, portrayed brilliantly by Helen Mirren."
She continued: "But nobody knows what drove her to become a DCI [Detective Chief Inspector] or want to join the police force in the first place. When you first meet her in the early 90s, she is a very complex character, but what made her so?
"I can't say too much now, but readers will find out next year when the book is published; or in 2016, which is the 25th anniversary of Prime Suspect, when they watch Tennison the series."
La Plante's new novel, Twisted, will be published on Thursday June 19 by Simon and Schuster UK.