After months of fevered speculation among fans, the producers of the film adaptation of EL James’s sadomasochism romance novel Fifty Shades of Grey have revealed the actors chosen to play the two leads.

The young woman Anastasia Steele and her wealthy older boyfriend Christian Grey will be portrayed on-screen by Dakota Johnson and Charlie Hunnam.

Johnson is the 23 year old daughter of the actors Don Johnson and Melanie Griffith, who’s previously had small roles in films including The Social Network and 21 Jump Street.

British actor Hunnam is ten years her senior. He was most recently seen playing the lead in Pacific Rim, and before that, as the hero in Deadfall.

With bigger stars having been linked to both roles in earlier stages of the film’s development, some fans of the erotic Fifty Shades books have expressed their reservations at the casting of lesser known actors.

The film, to be directed by Nowhere Boy’s Sam Taylor-Johnson, is due to be released next August.