Skarsgard fine with Avengers nudity

The 63-year-old Swede admitted he gets his kit off again in Avengers: Age Of Ultron, where he reprises his role as scientist Dr Erik Selvig.

"Yeah, I was naked again. They called my agent and said, 'Do you think Stellan will mind being naked?' My agent laughed his head off," he told Total Film.

The actor joked he insists on the nudity, saying: "I almost insist! Sometimes with a contract you get a nudity clause, which is fantastic. It's supposed to protect me from having my genitals exploited, which I doubt anybody would make a dime on."

Stellan, who next stars in Scandinavian thriller In Order Of Disappearance, said he is impressed with the film's success.

"I didn't have much clue about the Marvel universe at that time. What I said to Kevin Feige, the head of Marvel, was, 'All those superheroes? Still in those comic books? Can you make money out of that?' The whole table just froze and looked at me as if I was an idiot," he recalled.

"When I read the Avengers Assemble script, I said, 'F***, this is a masterpiece. How do you write a film with 10 leading characters and keep it going and keep your interest up?' That's an enormous achievement. He's (Joss Whedon) very smart."

Robert Downey Jr, Scarlett Johansson, Mark Ruffalo and Samuel L Jackson will reprise their roles alongside newcomers Aaron Taylor-Johnson, Elizabeth Olsen and James Spader in Avengers: Age Of Ultron, which opens in 2015.