Natalie Dormer has hit back at critics of 'In Darkness' over its ''gratuitous nudity''.

The 36-year-old star has co-written and stars in the new thriller opposite Ed Skrein, and she has responded to reviewers who suggested the sexual nature of the film was ''sadistic'' and unnecessary.

Firing back in an interview with The Guardian, she said: ''There has to be sexuality in the power play of a thriller. We have all got bodies, after all.

''In this film the sex scene, which for me was a lovemaking scene, is a metaphor for the way my character connects with the part played by Ed Skrein.''

The pair's characters come together after Dormer's character Sofia - a blind musician - overhears the murder of her upstairs neighbour, and she and Marc begin investigating the crime.

Explaining the importance of such a scene as displaying a ''connection'' between them, Natalie added: ''If the lead characters do not have a clear connection, then it doesn't work. And on screen it has to be a physical connection between two broken people. That was my intention.''

The 'Game of Thrones' star also insisted that such a raunchy scene means she and co-writer Anthony Byrne - who directed the movie - are actually keeping within the rules of the thriller genre.

She said: ''In a thriller the protagonists always have to join together somehow and sex represents that connection. If you are being true to the genre, you have to show this.''

'In Darkness' hit the big screen last month with an impressive cast also featuring Emily Ratajkowski, Joely Richardson, Neil Maskell, James Cosmo and Jan Bijvoet.