At the premiere of the film in Los Angeles, the 59-year- old actor said he was against the idea of using prosthetics to get the look of Churchill, reported Variety.
"I wasn't going to put on 50 or 60 pounds and put my health at risk so it was contingent on getting Kazuhiro to see if this thing was going to work.
"You could control the other component the energy, how he used his hands, the way he moved. But if you look ridiculous, it's not going to work. So you surrender to it," said Oldman.