VIGGO MORTENSEN stacks his case and suit protector neatly in the corner of the room. The precision of the movement is entirely in keeping with an angular formation of razor cheekbones and sharp suit. We probably shouldn’t be surprised the Danish-American-Argentine has this travelling thing down.

This is his final press engagement for David Cronenberg's A Dangerous Method, a film that pitches Mortensen's patriarchal Sigmund Freud against Michael Fassbender's corruptible Carl Jung. Keira Knightley's Sabina Spielrein, a former patient turned psychoanalyst, is the spank-happy nymphomaniac who comes between them. What's not to like?

“I thought it was a crazy idea when David came up with it,” says Mortensen. “But I just had this idea of a man with a beard. You don’t have to read far to discover a man who was ironic and funny and capable of using language as a weapon. I usually like to approach roles in a physical, non-verbal way. So this was a new way of working for me.”

Methodis Mortensen's third collaboration with the Canadian film-maker, gathering A History of Violenceand Eastern Promisesinto a (very) loose trilogy about civilisation and its discontents.

“With David it’s always about what’s lurking beneath,” says Mortensen. “He’s never obvious. There are only a handful of good film-makers who have been working for decades, and within that group they all eventually seem to slow down and play it safer or slip into self-parody.

“David may be the only film-maker I can think of who never repeats himself.”

Mortensen had already enjoyed an impressive career when he first met Cronenberg eight years ago. A polymath, the actor’s paintings and photographs hang in galleries around the world; he runs a publishing imprint; and he has recorded 10 albums.

Having grown up between Venezuela, Denmark and Argentina, he's capable of emoting across languages and took the lead in the 2006 Spanish-language swashbuckler T he Adventures of Captain Alatriste. (Of course he rides horses, and is an ace swordsman.)

But even before that, Mortensen had long been in demand among big-name directors and fellow thesps. He had popped up in Peter Weir's Witness, Brian De Palma's Carlito's Way, Jane Campion's Portrait of a Ladyand Sean Penn's The Indian Runner, when Lord of the Ringscame along and catapulted him into a more glittering limelight.

By the time Cronenberg's A History of Violencecame along, Mortensen had wrapped on Peter Jackson's epic Tolkien saga and had his pick of projects.

“I wasn’t sure about going to meet him,” he says. “I wasn’t sure about the script, and I admired the man and I didn’t want to waste his time. So I said to him on the phone that there were a few things I thought were too trashy and not real to me. And he said, ‘Oh, me too.’

“And that’s him. He wants to talk these things through. He wants to thrash out the details. He’s very flexible and playful as a director. He’s responsive.”

Cronenberg's methodology reigned on set, where Fassbender and Knightley proved accomplished pranksters. The larks continued on to the promotional tour. Mortensen turned up on The Late Showbefore Christmas and told David Letterman that Fassbender prepared for scenes by jumping repeatedly on one leg. Fassbender retaliated by claiming Mortensen liked to sit naked in a corner and eat a banana before filming.

Sadly, neither story is true.

“But they did play a lot of tricks during filming,” says a grinning Mortensen, without elaboration.

The new film, a British-Canadian-German co-production set between Zurich and Vienna, offers a frank and lively exchange of concepts: some intellectual, others sexual or downright deviant.

It's a showcase for Mortensen, his co-stars and an esteemed director. It ought to have been a heavyweight contender for awards season. But things haven't worked out that way. Barring a nomination for Mortensen's performance at the Golden Globes, A Dangerous Methodhas been almost entirely overlooked.

“I think the distributor just thought it would take care of itself in North America. But instead it disappeared. By the time they put it out wide they had missed a lot of top 10s and critics’ polls.

“David is my friend and he’s an incredible director. The fact he’s never been nominated for an Oscar is insane. When you see how many mediocrities creep in there and sometimes win. There are people out there with an Oscar for best direction who had no business being nominated in the first place. But David isn’t trapped by a certain style or expectation or perceived persona. That’s why he doesn’t calcify. Sometimes that works against him.”

Mortensen, a long-time political activist, has not been reticent about the ghosts in the Hollywood machine. Having carefully gravitated, post- Lord of the Rings,towards projects such as the Cronenberg films and The Road,Mortensen knows too well how potential "best pictures" can fall through the cracks.

“At one level,” he says in his low, Zen rumble, “you just don’t care. You don’t want to take it seriously. Everybody works hard to make a movie, but every year you look at the selections for acting and directing and cinematography at the Academy Awards and the Baftas and the Golden Globes and you find questionable choices.

"It's annoying at a creative level, but it's more annoying at a business level. For a certain kind of film – for a film like A Dangerous Method– having a garland on the poster can make a huge difference when it comes to someone choosing what they want to see that weekend."

It was worse watching John Hillcoat's adaptation of The Road disappearing from view, he says.

"Most years, it's just a puzzle. But for The Roadit was because of the Weinstein Company. Regardless of the contract they had with the film to put it out in a thousand theatres in the United States and to promote it appropriately, they chose not to. They had Ninethat year and focused all their efforts on that. They tried to sell what is really not a very good movie. But it almost worked. They got a few nominations out of it. But we weren't in there because our film was invisible."

It’s disappointing, he says, but there is a silver lining.

"The consolation is that The Roadis out there. The consolation is that people come across it and say, 'Well, why haven't I seen this before?' And I did get to work with Robert Duvall. I think since Gene Hackman retired, Duvall is the only American actor who just keeps going for the truth. And to watch him do that from one take after another was an incredible experience."

Later this year, Mortensen takes on Old Bull Lee – or rather a fictionalised William S Burroughs – in Walter Salles's adaptation of On the Road.

Cronenberg, meanwhile, has already wrapped on Cosmopolis, with Robert Pattinson. "I'm really pleased about that," says Mortensen. "It took him four years to get the last film made. We still didn't have all the funding in place when we started filming.

“It’s an insane business. Sometimes you’d think he’d never made a film before.”