Natalie Portman thinks lesbian sex scene is the selling point of Black Swan

Israeli-American actress Natalie Portman has said that her steamy lesbian love scene in 'Black Swan' might be the key to the thriller's success.

The star's lesbian sex scene with Mila Kunis served as a necessary selling point for the critically acclaimed film, she said.

"Everyone was so worried about who was going to want to see this movie. "I remember them being like, 'How do you get guys to a ballet movie? How do you get girls to a thriller? The answer is a lesbian scene. Everyone wants to see that," the New York Daily News quoted her as telling Entertainment Weekly.

The 29-year-old said that the dark love scene was the key to drawing both sexes to see the drama, which features Portman as an increasingly unstable ballerina who battles Kunis-her partner in that racy sex scene-and her own psychological demons.

Meanwhile, the physical and emotional stresses of the role took its toll on the actress, who reportedly lost 20 pounds in pursuit of a rail-thin dancer's physique.

"There were some nights that I thought I literally was going to die. It was the first time I understood how you could get so wrapped up in a role that it could sort of take you down," added Portman.