Diane Kruger's latest role led her to take up smoking.

The 41-year-old actress stars as Katja Sekerci - who loses her son and husband in a neo-Nazi terrorist attack - in the German drama film 'In the Fade', and Diane has admitted the tragic storyline left her feeling depressed and, ultimately, caused her to start smoking cigarettes.

She shared: ''[I] lost 7 pounds ... I felt like I was drowning in grief, drowning in the grey weather, and drowning in the story. I picked up smoking.''

The actress met with nearly 30 relatives of murder victims in preparation for her part in the Fatih Akin-directed film.

And Diane admitted that researching the movie changed her life ''forever''.

She told the New York Post newspaper's Page Six column: ''Grief is a weird thing, and I felt a heavy responsibility to find the truth and to honour the people that this has happened to.''

This comes shortly after Diane likened shooting the movie to having an ''out-of-body experience''.

The acclaimed star was named the Best Actress at the Cannes Film Festival for her role in the German-language film, and she's admitted that the production had a profound impact on her.

She previously said: ''It was such an out-of-body experience. There are scenes in the movie where I feel like I'm not acting; I'm reacting to what's happening in front of me. I was desperately searching for the truth.''

Diane also revealed she felt powerless to stop the dark thoughts from occupying so much of her free time.

She explained: ''It was definitely a very dark time in my life, where the border between what is my life and what is reality was really blurred. There was nothing I could do about it.''