The athlete-turned-reality TV star has been pictured sporting an increasingly feminine appearance in recent months, and he is expected to open up about his rumoured transition in an upcoming interview with U.S. newswoman Diane Sawyer.

The Rocket Man hitmaker was quizzed about the rumours surrounding Jenner during an appearance at a charity event in Los Angeles on Thursday (23Apr15), and the singer threw his support behind him, telling Access Hollywood, "I think anybody who comes out like that is an incredibly brave person. It's an incredibly brave thing to do, especially when you're older, I admire him for doing it and I support him 100 per cent... People should support him."

Jenner's highly-anticipated interview is due to air in America on Friday (24Apr15).