Noomi Rapace is the ideal girl with the dragon tattoo

When Danish director Niels Arden Oplev was casting Lisbeth Salander, the tattooed heroine in Stieg Larsson's international bestseller The Girl with the Dragon Tattoo, he was all too aware of Larsson's fervent fanbase.

Oplev needed an exceptional actress to play the troubled bisexual computer hacker with a taste for martial arts. He described Salander as "possibly the character in modern Scandinavian drama with the most expectations attached".

As a result, the director found himself "hysterical" about casting the film in 2007. He initially ruled out Noomi Rapace, then best known for her performances in several Swedish art-house films, because she was "too good-looking" and "too cute".

But Rapace fought hard to convince Oplev she was right for the role and spent seven months transforming herself to play the whippet-thin loner. "I wanted to be a bit more skinny, a bit more masculine... I was training martial arts like Taekwondo for four or five days a week with a crazy Serbian guy."

The result is a triumph, with rave reviews for Rapace's performance even from those film critics unsure about the movie as a whole. The Times critic Wendy Ide called Rapace the film's "main asset", adding: "It's hard to imagine an actress better suited to bringing Larsson's abrasive, strong-minded protagonist to life."

Fans of the book who have already seen the film before it opens in Britain today have also raved about 30-year-old Rapace, many saying that she is exactly how they had seen the character in their mind's eye.

The Girl with the Dragon Tattoo sees Salander join forces with campaigning journalist Mikael Blomkvist (played by Michael Nyqvist) to solve the three-decades-old murder of a young woman. It is the first in a series of books by Larsson called the 'Millennium Trilogy' and three more movies, based on the second and third books, are already in the can.

Given the trilogy's global success it was inevitable that Hollywood would muscle in on the franchise and an American version of Girl is currently in pre-production. Swapping Oplev's mostly dour bunch of unknown Swedish actors for a glamorous Hollywood cast is sure to boost the film's appeal - but the brilliant Rapace will be a hard act to follow. ·