(Cover) - EN Showbiz - Katy Perry covers all aspects of her marriage in her new movie as she wanted to show celebrities aren't "flawless".

The singer and Russell Brand are in the process of getting divorced following their split last year after 14 months of marriage.

The star shot a 3D documentary called Katy Perry: Part of Me during the relationship and decided to include a look at its breakdown in the movie.

"I thought it was important for me to show everything in between," she told talk show host Ellen DeGeneres.

"Sometimes people think that we're perfect and we know we're not at all. I think it's important to start breaking down the idea that to achieve your dream you have to be perfect or flawless or live in a fantasy world."

The star was keen to point out nobody's feelings will be hurt by the film. She also wants her fans to know a lot of what she experienced while shooting was fun and positive.

"So that's why I decided to put everything into the film in the most tasteful way. Mostly it's about how I got there and the ride along the way which can be bumpy but mostly is extremely fun," she added.

Katy Perry: Part of Me is due to hit theatres from July.

Justin Bieber will be appearing on Ellen's programme later this week and has told fans he has some exciting things to say.

"My friend @JustinBieber is here on Wednesday. I hear he has some big news," Ellen wrote on Twitter.

He replied: "@TheElleShow i do. #BELIEVEtour." (C) Cover Media