Nobody who saw Luc Besson’s electrifying thriller Léon could forget the disturbingly precocious performance of 12-year-old Natalie Portman as a brutally orphaned girl who apprenticed herself to a lonely hitman played by the French actor Jean Reno.

Since then Portman’s luminous beauty and screen presence have prompted comparisons with Audrey Hepburn and predictions that she is the next Julia Roberts. At 23 she seems on the verge of fulfilling that promise by beating her co-star Roberts to a nomination in the Golden Globe awards for her role in Closer, which opens this weekend.

The film, shot in London, also stars Clive Owen, a doctor whom Roberts falls for, and Jude Law, a writer captivated by Portman, who plays a New York stripper. The film is a four-handed game of deception, self-delusion and betrayal adapted by Patrick Marber from his West End play of 1994.

This intelligent work has clear appeal to the gamine, brown-eyed actress who is fluent in French, Hebrew and Japanese and whose recent completion of a psychology course at Harvard has lent her an earnest thoughtfulness quite at odds with the pole dancer she plays.

She has confounded assumptions that she would grow up to be a wild child like her fellow child star Drew Barrymore. “I’d never walked down the street on my own until I went to college,” she has admitted. “I never tried smoking. I don’t drink. I never tried any drugs.”

The only daughter of an Israeli father and an American mother, she has been outspoken on pro-Israel and liberal causes, drawing fire for joining John Kerry’s election campaign. She is an ambassador for a micro-finance organisation called Finca International, which helps women in developing countries.

Closer is the first film in which Portman has consented to play an erotic role since Léon, thanks to her trust in Mike Nichols, its 73-year-old director, whom she regards as a “second father”.

“When I was younger I wanted to stay away from doing overtly sexual roles because I didn’t want my public image to interfere with my personal development,” she said recently. By which she meant a flood of fan letters from men obsessed by a young Portman wearing lipstick, a choker and lacy Madonna-style gloves.

“All of a sudden I was reading reviews that were talking about the development of my breasts under my T-shirt,” she said. “That was so upsetting to me as a 12-year-old to read about.”

She reacted by going to the opposite extreme, but this did not prevent her becoming an international star who has worked for directors including Woody Allen, Michael Mann, Tim Burton and George Lucas.

She gained a huge following playing Queen Amidala in the three Star Wars prequels, the last of which, Revenge of the Sith, comes out this year. She was the attractive young mother in Cold Mountain, again appearing with Law. Most recently she was seen in Garden State playing a pathological liar with epilepsy.

Closer has been billed as her coming-out movie, but men who look forward to her performing as a pole dancer may be disappointed. Vital things do flutter to the floor, but only in the cutting room. The nude scenes were scrapped.

Portman says she came to an agreement with Nichols, who had directed The Graduate and with whom she had worked on his stage production of Chekhov’s The Seagull. “We would shoot everything and then we’d make a decision together,” she explained. While declaring that she was not against nudity in films, she thought it was “out of place”. It would be distracting to have “a flash of breasts” in the middle of the piece.