Michael Fassbender had to wear a giant fibreglass head during the filming of his new movie Frank

Los Angeles - Michael Fassbender felt "vulnerable" wearing a giant fibreglass head in his new comedy Frank.

The 12 Years a Slave actor, who plays tribute to musician Frank Sidebottom in the movie about an eccentric rock band, had to get used to wearing the giant prop in every scene.

He told The Guardian newspaper: "It was kind of weird in the beginning, the way it sits on your head. You feel a little bit vulnerable because you've not much peripheral vision. You can't hear that well either.

"But it's quite liberating as well, in the way that masks are. It's amazing how many emotions that face manages to convey. It can look vulnerable, it can look sinister, at times it looks confused."

He insists he eventually felt "comfortable" wearing the head and claims he decided to do the quirky film as a homage to Frank, the alter-ego of musician Chris Sievey, who passed away in 2010, even though he hadn't heard of the star, because he found the story funny.

He explained: "The script just made me laugh out loud. I thought there were also poignant moments there. It's a very unusual story, a real standalone. If it's refreshing to read, it's hopefully refreshing to watch."

Frank, which also stars Maggie Gyllenhaal and Domhnall Gleeson, premieres at the Sundance London film and music festival on Friday and will be released on 9 May.

Watch the trailer here: