Katy Perry has hinted that Russell Brand was "threatened" by her career.

Speaking in her documentary Katy Perry: Part of Me, she explained: "I thought to myself, 'When I find that person that's going to be my life partner, I won't ever have to choose [between the partner and my career]. They won't be threatened or have weird motives.' Then I started to realise, that's not true."

Perry – who split from Rock of Ages star Brand in December after 14 months of marriage – claims that she did everything in her power to save her marriage, before being forced to acknowledge that it was over.

She said: "I have that same belief system with everything, from career to my life to my personal life, everything. And I will do everything it takes to not fail. And I did everything it took, but it still failed."

Perry said that she wanted her 3D documentary – which was shot around the time her marriage to Brand was crumbling – to reflect her personal struggles in order to show it is possible for people to bounce back from their difficulties.

She said: "I think if you were to see the movie and it was completely avoided, you'd think, 'Hmm that's strange, I know something else happened in her life last year.'

"So I wanted to handle it delicately with the most integrity I could and show, 'Yeah I'm going through the same situation that half of America goes through and somehow I landed on my feet, so you don't have to lay down and die like you think.'

"Just because you're in the spotlight doesn't mean you get to dodge the curveballs - they're actually bigger."