In his interview the Frank director said after working with the actor on music for the film, he believes Michael has what it takes.

"He is definitely good enough. He's got all this charisma anyway which is what you need to front a band," he said.

"He's got a really good strong voice but I think he's probably got his hands full at the moment but if he wanted to do it he could certainly do it."

Speaking at the launch of the ICCL Human Rights Film Awards, the Irish director revealed the Frank soundtrack will be out soon, with Fassbender tracks never heard before.

"We're bringing out the soundtrack really soon, we're putting it together.

"There's a huge amount of music that was made but was left out of the film," he told.

"There are all these tracks that were recorded and actually filmed that didn't make it into the final cut so there's a whole lot more music.

"So what we're going to do is release a big soundtrack with all the songs in the film plus lots of extra material as well."