Austin Butler said he had been surprised to learn that Elvis Presley had a twin after taking on the role of the legendary rock star for a new biopic.
The actor, 30, said he had learned “a whole bunch of things” about the King of Rock n Roll and promised that audiences would too.
Butler stars alongside Tom Hanks in Elvis, directed by Oscar-nominated filmmaker Baz Luhrmann.
Speaking at the London premiere about filming he told the PA news agency: “It was the time of my life, it really was, it was such a privilege.
“I knew his work before and I had a very peripheral understanding of his life so I learned a whole bunch of things about him.
“I didn’t know he was a twin when I first started, did you know that?”
Elvis’s twin brother Jesse died at birth in 1935.
Of the movie, Butler added: “You get to see a lot of things.”
Butler described Luhrmann as “one of the most incredible people on this planet,” who had “such a singular vision” for the film.
“We had an absolute ball getting to create this together,” he said.
Elvis is scheduled for nationwide release by Warner Bros Pictures on June 24.