Austin Butler felt an "immense amount of fear" playing Elvis Presley.

The 30-year-old star plays the King of Rock and Roll in Baz Luhrmann's hotly-anticipated biopic 'Elvis' and explained that he was daunted by his portrayal of the late music icon.

Speaking to the i newspaper, Austin said: "I felt such a responsibility to Elvis, his family, all the people around the world who love him so much. So it was an incredible amount of pressure – and with that comes an immense amount of fear."

The actor revealed that it was only when he filmed his first concert sequence as Elvis that he realised he had what it takes to bring the King to life.

Butler recalled: "I started feeling this energetic exchange. And so I allowed my imagination to just truly accept that this is the '68 Special', I'm doing this for this audience right now. My career is on the line.

"I looked at myself in the mirror – I'm dressed in the leather, covered in sweat. And I had this moment where suddenly I was like, 'OK I can do this.'"

Baz revealed that he was uncertain about choosing Austin to play the lead role but was persuaded by a call from Denzel Washington – who was impressed by the actor's work ethic when the pair worked together on Broadway.

The 'Moulin Rouge!' director explained: "I'm not sure I chose Austin. I did in the end – I put him through the wringer. But I'm starting to feel like he kind of chose me."

Austin has explained how he has dedicated years of his life to his depiction of Elvis and Baz feels that the approach was the only way to make the biopic a success.

The filmmaker said: "He's been living Elvis for three years. And I think that was the only way, because he didn't want to do an impersonation."