Eddie Redmayne has compared Caitlyn Jenner's transition to a ''civil rights movement''.

The 'Theory of Everything' actor is set to play transgender artist Lili Elbe in 'The Danish Girl' and has confessed he admires Caitlyn - who was known as Bruce before her transition - for having the ''courage'' to open up about her struggle.

He said: ''I absolutely salute her courage. Hers is a very specific story, and it's one that shouldn't stand for everybody's. But it is amazing what she's gone through and how she's done it. It's a civil rights movement.''

The 33-year-old star underwent three years of schooling by the trans community to help prepare him for the role and has admitted it changed his own views, making him realise that gender is ''fluid''.

He told the latest issue of Out magazine: ''My greatest ignorance when I started was that gender and sexuality were related. And that's one of the key things I want to hammer home to the world: You can be gay or straight, trans man or woman, and those two things are not necessarily aligned.''

Eddie - who won an Oscar for his portrayal of Stephen Hawking - also admitted he feels a sense of ''responsibility'' to those who shared their experiences with him.

He added: ''People were so kind and generous with their experience, but also so open. Virtually all of the trans men and women I met would say 'Ask me anything.' They know that need for cisgender people to be educated. I felt like, I'm being given this extraordinary experience of being able to play this women, but with that comes this responsibility of not only educating myself but hopefully using that to educate [an audience]. Gosh, it's delicate. And complicated.''