`The Killer Inside Me` was difficult: Jessica Alba

London: Hollywood actress Jessica Alba`s latest movie `The Killer Inside Me` was a `difficult movie to shoot and it`s difficult to watch`.

"It stays with you, especially this. It`s a difficult movie to shoot and it`s difficult to watch. It`s about a very dark subject so I think if you are being true and authentic then it does definitely affect you," contactmusic.com quoted her as saying.

The 29-year-old actress plays Joyce Lakeland in the Michael Winterbottom directed thriller movie which tells the tale of a Texas policeman who is slowly discovered to be a psychotic murderer and she admits the film is hard to watch.

Kate Hudson revealed she too had difficulty filming the movie especially intimate scenes with Casey Affleck.

"We were working in a really intimate setting so it was really just me and Casey and the director Michael in a room together being able to sort of, fool around with the scenes and get to that place and feel like we can just be intimate. There is some a*s slapping involved," said Hudson.

"The Killer Inside Me" is due for a limited theatrical release in the US June 18.