(Cover) - EN Showbiz - Natalie Portman believes everyone has a dark side to their personality.

The 29-year-old has attracted huge attention following her role in soon to be released movie Black Swan. The actress plays ballerina Nina Sayers who while competing for a prestigious role with the New York City ballet company discovers a more sinister side to her character.

The actress believes Ninas predicament is mirrored within society where people often have multiple sides to their make-up.

I think everyone has a little bit of both, I dont think anyones all white or black. Weve all got that purity and impurity battling inside of us, she told Cover Media.

Natalie has already spoken of the pain she endured in order to authentically profile the life of an average ballet dancer. Through tales of intense weight loss and 20 hour working days, Natalie confirms she often went past her own pain threshold in order to do the film justice.

She had no idea just how difficult the part would be until she started filming, but even then things didnt get easier. The star worked with various ballet teachers, choreographers and coaches, and wasnt prepared for how hard that would make shooting.

All of them really shaped it and many of them were there during filming to give me notes. After every take I had five people giving me notes, Darren [Aronofsky, the director] plus all of these ballet experts, she explained. You really understand the discipline, the rigour, the willingness to work through physical pain. You really go through everything and that was really helpful in building a very, very detailed back story for this world.

Black Swan is released in the UK on January 21. (C) Cover Media