Keira Knightley reveals how she filmed explicit scenes in new movie

British actress Keira Knightley has revealed how she managed to film the explicit sex scenes in her new movie 'A Dangerous Method'.

The 26-year-old plays a sex-starved psychiatric patient who enjoys masochism called Sabina Spielrein. She is treated by renowned psychoanalyst Carl Jung, who is played by Michael Fassbender.

She told Culture Magazine: "We had one or two shots maximum. It was a vodka shot to calm our nerves and away you go really.

"Then we had champagne. We drank quite a lot of champagne, actually."

In the film, which is due for release on 10 February 2012, Knightley's character falls in love with Jung, which causes trouble for his working relationship with Sigmund Freud, who is played by Viggo Mortensen.

Knightley has made a name for herself in family films such as 'Bend it Like Beckham' and 'Pirates of the Caribbean', as well as period dramas including 'Pride and Prejudice' and 'The Duchess'.

She explained at the Venice Film Festival that she loves acting in period dramas as she is interested in history.