A woman lay behind the creation of Dr Jekyll and Mr Hyde, the author of a new book has claimed.

Mrs Jekyll and Cousin Hyde, by Jeremy Hodges, said that Robert Louis Stevenson's cousin, Katharine de Mattos, read him horror stories by Edgar Allan Poe as he recovered from a severe illness.

He contends that it led not only to Stevenson’s famous dream which inspired Strange Case of Dr Jekyll and Mr Hyde sprang but also another horror story on the theme of two people fighting for control of one body.

However Katharine de Mattos’s Through The Red Litten Windows was not published until six years later under a male pseudonym.

Hodges said: "Without Katharine, who kept Stevenson alive and helped nurture his love of horror stories, there would be no Jekyll and Hyde.

"They had been very close, with Stevenson helping her to survive an unhappy marriage and make a living as a single mother by writing, but they fell out after a row over one of Katharine’s stories allegedly ‘stolen’ by Stevenson’s wife.

"Stevenson dedicated Jekyll and Hyde to Katharine with a charming little verse but never explained why. It’s a very sad story, and it’s time Katharine’s side of it was told."

Mrs Jekyll and Cousin Hyde, by Jeremy Hodges, is a limited edition free download at www.cityofliterature.com.

Strange Case of Dr Jekyll and Mr Hyde was first published in 1886.

Katharine de Mattos who was at Stevenson's home in Bournemouth when the story was written.

She had accompanied her cousin and his wife Fanny on a trip to the West Country to visit Thomas Hardy when Stevenson suffered a major haemorrhage in a hotel.

The two women struggled all night to stem the outpouring of blood and eventually got the author safely home, where to while away his convalescence Katharine read him horror stories by Poe.