Katy Perry
Katy Perry's new film Part of Me could portray ex-husband in a negative light Reuters

Katy Perry's ex-husband, Russell Brand, is dreading the release of her new concert movie, Part of Me, set for release in July.

According to OK! magazine, Perry ignored his pleas to leave footage of their turbulent 14-month marraige on the cutting room floor that could severly dent his "cheeky-chappie" image.

"It was important for me to leave some of the more difficult things in the film so that it wasn't just a narcissistic fanfare film about how great I am," she said.

"Because I'm not all great. There might be moments of greatness but they are very hard-worked [sic]. It was important to show that there are obstacles and problems in people's lives and it's OK if you have them. You just have to overcome them.

"Sometimes, if you want to achieve something great, there will be curveballs. You just have to dodge them every once in a while," she told AP.

The British comedian, currently starring alongside Tom Cruise in Rock of Ages, has already shown he is very touchy about the subject, having thrown a masssive strop when TV presenter Graham Norton brought up the subject of his divorce on a recent show.

Ignoring the question, Brand, 37, looked to his mother Barbara, 65, seated in the audience, and accused Norton of making her cry.

Norton, 49, defended his line of questioning, insisting it would have been strange not to mention his ex-wife after she appeared on the very same sofa a week earlier.

But Brand could yet be exposed as a hypocrite in Perry's documentary with some hard-to-watch scenes in which he leaves his wife weeping floods of tears.

One scene in Katy Perry: Part of Me shows Brand lecturing her about being overweight just moments before she is due to hit the stage at a concert.

Tears can clearly be seen streaming down the 27-year-old singer's face after he berates her: "You need to get in better shape."

In another scene, Perry and Brand, 36, are seen and heard bickering over conflicts in their personal schedules.

When she makes a suggestion over how to align their diaries, he dismisses it, snarling: "Don't be so stupid."

But however bad it looks for Brand, it could have been worse. Perry said a lot of drama she self-censored: "I didn't get too detailed about the specifics because I believe that that's only supposed to be between the two people that are in it, but I just wanted to encourage people to let them know that it's OK if they have problems, it's OK if they're going through a situation, they don't have to lay down and die. They can get through it," she said.

The film, which will be distributed worldwide by Paramount, is still undergoing final editing but is scheduled to hit British and American screens on 5 July.

Its release will come just nine days before their divorce becomes official on 14 July.