Effing, blinding (two swear words a minute) and flirting for Crouch End, Gillian Anderson could not be less like her chilly screen persona, Kevin Maher discovers

In a tiny trailer, in a clearing in a cold and wet Worcestershire forest, Gillian Anderson is swearing like a docker. “Movies should be whatever the f*** they are!” says the 38-year-old actress and one-time TV icon from The X Files. “If they are f****** disturbing, then let them be f***** disturbing!”

Anderson in the flesh, impassioned and excitable, in black overcoat and blonde hair, is an arresting expletive-spewing inversion of a screen persona that often tends towards self-possessed froideur. She is here facing her final week’s work on the thriller Straightheads, and is vociferously defending the film’s bleakly violent tone.

The movie, about a young urban couple, Alice (Anderson) and Adam (Danny Dyer), who are brutalised by a gang of country yokels before extracting even more gruesome revenge, will not be everyone’s cup of tea. “It’s dark, but it’s brilliantly dark,” Anderson says about a movie in which gang rape, torture and the near lethal intrusion of a rusty gun barrel into the rectum of a major character are key features. “We can’t pretend that there isn’t violence in the world, that it doesn’t f****** happen!”

And with that she’s ushered on set, handed a hunting rifle, plopped into a 4x4, and sent tearing down a muddy path to a bloody appointment with cinema destiny.

Flash forward 15 months and Anderson, now mousy brown in floral-print blouse, sits sprawled on a couch in a spacious London hotel room. Straightheadsis close to release and the actress is as staunchly support-ive as ever, only this time without the expletives. “Look, I swear a lot normally,” she admits, before shifting the blame on to her co-star, the notoriously potty-mouthed Dyer. “But working with Danny exacerbated it. I mean, we all absorbed the word c*** into our vocabulary thanks to him.”

Thankfully, with or without four-letter frippery, she is still uncharacteristically ebullient. Indeed, there is something about her, some twinkly-eyed defiance that was criminally untapped by both The X Files and her recent period epics ( The House of Mirth and Bleak House) that suits perfectly the audience-baiting aggression of Straightheads. As if to prove a point, during the long months of the movie’s postproduction, Anderson divorced her second husband Julian Ozanne, had a baby boy with new boyfriend Mark Griffiths, snagged a Bafta nomination for Bleak House, moved out of her home in Notting Hill, polished a near-complete draft of her debut screenplay The Speed of Light, and kick-started her career as a movie producer by optioning the rights to a biography of the acclaimed war reporter Martha Gellhorn.

She says that playing Alice was just what she needed at the time, just the sort of direction she wanted to go in. But, ultimately, is the character of Alice – wealthy, sexually available and coming on to blue-collar handyman Dyer like a freight train – not something of a male fantasy? “It’s quite possible,” she says, smirking. “But, thinking about my own life, I once asked someone out that I met in a movie theatre.”

That’s a bit creepy. “It wasn’t actually. We had a six-month relationship after it. We just started chatting on the way out, and I asked him if he wanted to go for tea.”

What was the film? “ Amélie.” That’s sooo the type of film that would make you go out with someone. You wouldn’t do it after Straightheads.

“Well, maybe it’s just me, but things like that happen all the time. I remember meeting this one guy, and two days later he phoned me and asked me to go to Paris with him for the weekend. And we did.”

I think it’s just you. “I think you have quite a boring life.”

OK, so what about the film’s sex and violence? It’s very dark and disturbing, no?

“Obviously, yes,” she says. “The way Danny’s character eventually mixes sexual and violent impulses together. But they can be interrelated. There are lots of examples from . . . er, why are you grinning?”

Sorry. I just thought you were going to give me an example from your private life where sex and violence were interrelated.

She giggles. “Well, as it happens . . .”

Let me guess. You were in Paris with this guy . . .

Although American born, Anderson was famously raised in Crouch End, North London, from the age of 2 to 11 while her father pursued a career in film postproduction. When she moved back to the US, this time to Michigan, she felt intensely isolated and, despite claiming peripheral membership of the punk music scene, she says that she didn’t really belong anywhere until she started acting in college.

So, did you become an actor because of your family background, because your identity was constantly in flux, or because you just liked showing off?

“Did you smoke a few joints before writing these questions?”

No. “Well, then, I became an actor because it was the only thing I could do. I didn’t have any friends, I didn’t fit in. But when I started acting everything in my life shifted and I felt happy.”

She did theatre work in New York (including appearing opposite Brenda Blethyn in Alan Ayckbourn’s Absent Friends) and then, at the age of 24, landed the role of a lifetime as Dana Scully, an investigator of the paranormal, in The X Files. The series, both paranoid thriller and sci-fi hokum, lasted for nearly ten years, made Anderson a household name, gave her a first husband in the show’s art director Clyde Klotz (with whom she had a daughter, Piper), and allowed her the luxury to pick and choose the projects that came in its wake – mostly quirky indies such as Playing by Heart and A Cock and Bull Story.

She is excited, she says, about her new career momentum – about directing her own script, and producing and starring in the Gellhorn biopic. As she is excited by her recent move with Griffiths, her businessman boyfriend, to the relatively anonymous “outskirts” of London. “I just wanted to be able to walk outside my door without worrying about photographers,” she says.

And still, does she never think about what might’ve been if, back in 1993, the X Files producers had gone for the bigger-name actresses that Fox Television was pushing? “Breastier,” she says.

I’m sorry? “They didn’t want bigger actresses, they wanted more of a Pamela Anderson type. You know, breastier.” I didn’t know there were breast issues. “It wasn’t just breasts. It was taller, leggier, blonder and breastier. The whole works.”

OK, but if they went for breasts instead of you, where would you be now? “Not here. Not on this couch. Possibly in England. And definitely acting.” Would you be happy? “Probably.”

Happier? She winces. “That’s an awful question. But I probably wouldn’t be able to make the career choices that I’m making.” Yes, but you might have bagged an Oscar-winning role in the meantime and gone in a completely different direction.

“What does that mean?” she replies, beaming, eyes twinkling. “Rather than making movies about f***ing someone up the a*** with a gun?” Straightheads is released on April 20

The Anderson files: her screen highlights

The X Files (1998)

Reprises her star-making role as Dana Scully from the small screen to dig deeper into the conspiracy of alien invasion. Also sends up the Scully character in The Simpsons.

Playing by Heart (1998) Plays a theatre director as one of several couples talking about love in this romantic roundelay that also features Sean Connery, Angelina Jolie, Dennis Quaid and Gena Rowlands.

House of Mirth (2000) Gets to act everything from pillowy-lipped lust to abject despair in Terence Davies’s adaptation of Edith Wharton’s novel about upper-class New York at the turn of the 19th century.

Bleak House (2005) An acclaimed performance as Lady Dedlock in this award-winning BBC version of Dickens.

The Last King of Scotland (2006) Is the object of James McAvoy’s desire in Idi Amin’s regime as the wife of another medic in this adaptation of Giles Foden’s novel.