How did Agatha Christie become the best-selling novelist?

On 12 January 1976, author Agatha Christie died peacefully, aged 85.

By the time of her death, Christie had written more than 80 books. Most of her works were detective novels but she also wrote romances, short stories, poetry and plays. She created the detectives Hercule Poirot and Miss Marple.

But how did she become the best-selling novelist of all time? Megan Jones explores elusive author's methods through rare archive interviews.

(Picture: Agatha Christie, Credit: PA Media)