British actress Hayley Atwell has caused a storm by dismissing critically acclaimed movie 12 Years A Slave as "torture porn".

The Captain America: The First Avenger star sparked a debate on when she shared her thoughts on Steve MCQueen's movie, which tells the true story of a free man who is kidnapped and sold into slavery.

Atwell described the real life story as "remarkable" but criticised MCQueen's inclusion of scenes depicting brutal rape and violence.

In a series of posts on, she writes, "Ok. I'm going to say it. 12 Years a Slave...' movie.. felt like a film for ignorant middle class white people. Yes. I'm saying it.... But the true story is remarkable and important and the film was torture porn."

12 Years A Slave received nine Academy Award nominations including Best Picture and Best Actor for its star Chiwetel Ejiofor.