Daniel Radcliffe's stiff Swiss Army challenge

Daniel Radcliffe says playing a corpse was a 'massive challenge physically'

It's been the most talked about film at the Sundance Film Festival, and it stars Harry Potter actor Daniel Radcliffe. But Swiss Army Man, a feature film debut by directors Daniel Kwan and Daniel Scheinert, is achieving headlines for two reasons - not only has its sensationalist plot divided critical reaction, but Radcliffe plays a dead body with flatulence issues.

Speaking as the film had its world premiere at the Sundance festival in Utah, 26-year-old Radcliffe called making Swiss Army Man "one of the most joyous experiences of my entire life".

Yet the media had differing opinions with Rolling Stone calling it '"Sundance's craziest movie" and the Guardian's headline reading "Daniel Radcliffe's flatulent corpse prompts Sundance walkouts" - a reference to the amount of people who deserted the premiere, apparently in disgust.

From start to finish, Swiss Army Man is controversial. Paul Dano, currently starring in the BBC drama War and Peace, plays Hank, a lonely young man on the shore of a desert island.

He is thinking about finishing it all, when the body of Radcliffe's character is washed up. Manny, as the corpse is called, can't control any of his bodily functions, but his gaseous presence saves Hank's life, and he's not prepared to let him go, taking him bodily back into civilization.

Directors Daniel Scheinert (left) and Daniel Kwan (right) - joined here by cast members Daniel Radcliffe, Mary Elizabeth Winstead and Paul Dano (second right) - call themselves the 'Daniels' and are known for making music videos

Dano says he spent most of the weeks of filming "dragging Dan's corpse around the woods". But Radcliffe, far from having an easy job, says he found playing a dead body a difficult move.

"It was a massive challenge physically," he says, "I mean he's dead, rigor mortis is setting in, so everything has to be said with the eyes. It was weirdly emotional, playing a corpse, but I'm really pleased about just how dead I look in the film."

The actor, who after finishing Harry Potter, has taken parts such as beat poet Allen Ginsberg in Kill Your Darlings, and Igor in Paul McGuigan's gothic Victor Frankenstein, admits "a liking for the strange and fantastical".

"Why did I take this part? Well, why not? I think it's a fantastic and important movie and it's just an amazing work of imagination."

Kwan and Scheinert, Americans who met at a college animation class, collectively call themselves the "Daniels", and are known for making music videos, as well as a short film called My Best Friend's Sweating.

They say that after writing Swiss Army Man they "thought we would just have to act in it ourselves, because the plot is so crazy, we really thought we would never get any actor to do it".

Paul Dano's character (pictured) 'uses and abuses my character's body', says Daniel Radcliffe

Radcliffe says: "I didn't know what I was doing until I turned up, even though I had read the script. In fact I didn't know what I was doing from day to day. As you'll see if you watch the film, it was a hard one to be prepared for. But I had such a good experience.

"A lot of my friends would say that playing a dead guy is a good role for me, I took some flak on that before I even filmed it. I don't want to say exactly what happens to me, apart from getting lugged around by Paul Dano, but his character uses and abuses my character's body.

"It's going to split opinion, it's going to be divisive, and you're either going to love it or hate it. There's something very, very absurd about the movie."

But Radcliffe denies that his heart now lies in independent film-making, saying "people should stop thinking big budget films aren't a challenge to make for actors".

"I am sure I'll do one again sometime. For me, it's all about the freedom to do what project I want at the time. "

Now living in New York, Radcliffe was due to take a part in a John Krokidas comedy about George W Bush's senior advisor Karl Rove, but the project is on hold. However, taking such a controversial role in Swiss Army Man will do his career no harm.

According to trade magazine the Hollywood Reporter, it has all the makings of a cult classic. It says: "By turns enchanting, irritating, juvenile and yet oddly endearing… Swiss Army Man will probably make very little money theatrically. But over the long haul, there will be plenty of punters willing to watch it."

Radcliffe himself says he has no regrets: "This is a film where cinematically, anything goes. It's crazy and wild. Am I happy I did it? You bet."

The Sundance Film Festival runs until 31 January. Swiss Army Man is yet to receive a release date in the UK.