Sam Taylor-Johnson is set to direct the forthcoming Fifty Shades of Grey adaptation.

There has been mounting speculation over who would take directing the movie, with author EL James finally revealing the news yesterday via her Twitter.

She wrote: "I'm delighted & thrilled to let you guys know that Sam Taylor-Johnson has agreed to direct the film of Fifty Shades of Grey."

Taylor-Johnson is best known for directing the 2009 John Lennon biopic Nowhere Boy, which stars her husband Aaron Taylor-Johnson.

The director said of her latest undertaking: "I am excited to be charged with the evolution of Fifty Shades of Grey from page to screen.

"For the legions of fans, I want to say that I will honour the power of Erika's book and the characters of Christian and Anastasia. They are under my skin too."

Erotic romance novel Fifty Shades of Grey is the first instalment of the Fifty Shades trilogy that delves into the relationship between a young college graduate Anastasia Steele and a mysterious business magnate Christian Grey.

Speculation continues as to who will take on the lead roles in the movie adaptation, with actors such as Channing Tatum, Emma Watson and Mila Kunis previously being linked to the film.