She came to fame as the girl with the dragon tattoo, but Noomi Rapace has no intention of doing an Angelina Jolie and having her skin inked for real.

“How does she do that?” the Swedish actress muses. “I mean, if she’s playing somebody from the Second World War, do they cover them all up? I can’t tattoo myself – I must be a chameleon. I have to change the way I look for different characters.” She’s not kidding. When we meet, the 32 year old is almost unrecognisable from the role that made her name – stick-thin, hard-faced hacker Lisbeth Salander. Noomi (who never even considered starring in the recent Hollywood remake of The Girl with the Dragon Tattoo, saying, “I’ve already played her and I want to do other things”) is back to a healthy weight, with curves in all the right places. And she’s looking rather more photogenic with the long dark locks that define her recent role, as gypsy fortune teller Madame Simza in Sherlock Holmes: A Games of Shadows.

If she’s playing somebody from the Second World War, do they cover them all up? I can’t tattoo myself – I must be a chameleon. I have to change the way I look for different characters. “I was really nervous before,” says Noomi, who had little time to research the role. Apparently, a brief meeting with Robert Downey Jr and his producer wife Susan sealed the deal just six weeks before filming. “It was a good, quick meeting in LA,” recalls Noomi. “I walked out of it, called my manager and I was like, ‘Wow, those two are amazing. I would love to work with them.’”

Given the current craze for all things Scandinavian (Danish drama The Bridge has had rave reviews, and even the Duchess of Cornwall is a fan of The Killing, with a Sarah Lund sweater to prove it), Rapace is on a roll right now. After Guy Ritchie snapped her up for the second Holmes and Watson adventure, Brian De Palma signed the star for a new drama called Passion and she recently wrapped Ridley Scott’s sci-fi thriller Prometheus opposite man of the moment Michael Fassbender. “I just came back from space and it feels really weird to return to Earth again,” Noomi smiles, but then her life has been a bit of a blur since the Dragon Tattoo trilogy. Having worked steadily in Swedish productions until her 2009 breakthrough, Noomi admits that the switch to Hollywood has been a little hectic. “It was super intense and so much fun,” she says of her Sherlock Holmes experience.

“But I’ve done a lot of preparation for most of the movies I’ve worked on before. I’ve known about them long before filming started – I’ve prepped and I’ve changed my body and done research.” She certainly went that extra mile to play crime-fighting hacker Lisbeth Salander. For one thing, she was prepared to get proper piercings. “Those were real,” she confirms of the rings through her nose and ears. “They said I could have fake ones, but I didn’t want to. I wanted to feel those piercings.” She also embarked on a hard-core physical programme for the role.

“I did a lot of training for The Girl with the Dragon Tattoo – a lot of martial arts, kick boxing and Thai boxing – and it was pretty hard,” she admits. “But Lisbeth’s athletic, so I wanted to be more like a boy in my appearance.” Luckily, Noomi loves a good fight, at least when she’s acting. “I always enjoy that,” she smiles. “And I try to do as much of the stunt work as they will allow me to do. You just have to sort of crack on and do it. Of course, you’re bruised and your body is aching and you hurt yourself sometimes, but that’s part of it.” Not surprisingly, Madame Simza was a far more sedentary role. “It’s a period piece and you don’t want to look like you’ve just stepped out of the gym,” says Noomi. But the actress wasn’t content to rest on her laurels, and got to work researching how gypsies lived back in the 1890s.

This was of particular interest to Rapace, who believes she has Romany blood from her father’s side (the daughter of a Swedish actress and a Spanish flamenco dancer, Noomi left home at 15 and enrolled at theatre school in Stockholm). “When everyone else went wild, I was sober,” explains Noomi, whose parents split when she was young. “I was acting in a soap opera when I was 16, so I suddenly grew up.” The soap meant she could be self-sufficient, which – after a ten-year marriage to actor Ola Rapace that ended last year – she still is: “I think of myself as a survivor and I’m pretty stubborn.” No wonder Noomi was drawn to Sigourney Weaver’s tough-cookie Ripley in Alien.

“It was the first time I saw a woman doing things that men had always done before,” she says of the sci-fi action heroine who outlasts her male colleagues. As an Alien fan, Noomi was thrilled to join the cast of its forthcoming prequel Prometheus. She plays a scientist named Elizabeth Shaw who has a lot of Ripley’s toughness, and being in a Ridley Scott film should bring other big-name directors and well-paid projects calling. That’s good news for Noomi, who has an eight-year-old son, Lev, to take care of. But she’s not sure if she’ll ever settle in Hollywood, or indeed anywhere.

“I’m always travelling and moving around,” she says. “I’ve always felt like an outsider in Sweden. I haven’t really found ‘home’ yet. I’m half Spanish but I don’t speak it. I speak a bit of Danish, a bit of Norwegian, Icelandic and English. I’m something in between.”

Sherlock Holmes: A Game of Shadows is out on DVD and Blu-ray tomorrow. Prometheus opens on June 1.