London, Nov 16 : Keira Knightley has admitted that she necked vodka shots to get through explicit sex scenes in her upcoming movie `A Dangerous Method' in which she plays an erotically charged mental patient.

The 26-year-old actress, who has never faced problems getting her kit off for films, needed a little courage when it came to playing a sex-obsessed seductress.

Some of the sex scenes in the movie were so explicit that the `Princess of Thieves' star initially turned down the role and then had to swig vodka to get through them.

Knightley plays a masochist who has an affair with her psychoanalyst Dr Carl Jung, played by Michael Fassbender, and at one point she is tied to a bed, topless and spanked.

"We were both very nervous about those scenes because they're not nice," the Mirror quoted her as saying.

"When we shot them I said to Michael, `If you touch me I'm going to kill you.

"He said, `Keira, you're tied to the bed at the moment. I don't think you're in any position to say that.

"I said, `Yeah, you're right.

"He's absolutely wonderful - we had a couple of shots of vodka before doing the scene and a couple of glasses of champagne afterwards. A lot of people say acting is like therapy but I don't go for that. It is for some people, but not me.

"When you're playing something so dark you want to have a really nice time afterwards otherwise it's far too depressing.

"The actual filming work was very focused and very creative, but at the end of the day we watched football - the World Cup was on - and drank beer," she added. (ANI)