Fifty Shades of Grey director Sam Taylor Johnson has revealed that she and author E.L. James had "proper on-set barneys" about the treatment of the movie.

The director told Porter magazine that they had to resolve their creative differences to make a film they were both happy with.

She explained: "It was difficult, I'm not going to lie. We definitely fought but they were creative fights and we would resolve them.

"We would have proper on-set barneys, and I'm not confrontational, but it was about finding a way between the two of us, satisfying her vision of what she'd written as well as my need to visualise this person on screen but, you know, we got there."

When asked if she and James were now friends, she said "Ummm." The magazine's features director Vassi Chamberlain said she did not need to answer the question, to which she replied "Good."

The director also spoke about why she wanted to take the helm of the big-screen adaptation of the best-selling novel, saying: "I just knew I wanted to make this film.

"I knew how it should be made, needed to be made, and I felt a certain responsibility to make it the right way.

"I felt it was an incredible story. It's like a dark twisted fairy tale, very romantic, and it was interesting how troubling it was, and how romance and the darkness interweaved."

Fifty Shades of Grey is in cinemas on February 13.