Fifty Shades of Grey producer Dana Brunetti has reacted to the backlash from fans about the film's casting.

Following yesterday's announcement that Dakota Johnson and Charlie Hunnam will play Anastasia and Christian Grey, upset fans let their views known on Twitter.

In an interview with Indiewire, Brunetti responded to the backlash: "You could never meet the expectations of so many who have visualized their different ideas of characters from how they read it in a book.

"While some are upset that their favourite wasn't chosen, there has been a massive response and excitement to Charlie and Dakota from the fans.

"Ultimately we cast who is right for the role on many factors, but most importantly the chemistry between the two, and it is great between Dakota and Charlie."

Fifty Shades of Grey is due for release on August 1st, 2014.