Miss Marple based on Christie's granny

Rex Features

Secret tape recordings of writer Agatha Christie have revealed that she based her character Miss Marple on her own grandmother.

The reels were discovered by Christie's grandson, Mathew Prichard, at her Georgian mansion and were recorded by the author in the 1960s for an autobiography, The Mirror reports.

She said of her grandma: "Although cheerful, she expected the worst of anyone. With frightening accuracy she was usually proved right."

"I shouldn't be surprised if so-and-so was going on," she said her gran would comment. "And that was exactly what was going on."

In the reels, Christie revealed that her famed characters Poirot and Miss Marple would never meet because he "would not like being taught his business by a spinster".

Prichard, who found the reels in a storeroom, said: "The one thing you can always credit Agatha with is an unending capacity to surprise. I am overjoyed."