The Girls Aloud star, who is gearing up to release her debut album Cinderella's Eyes later this year, said that she was "desperate" to work with the 'Wuthering Heights' singer but her label failed to track her down.
"I wanted Kate Bush," she said in an interview with Digital Spy.
"I don't think anyone knows where she is to be honest. I kept asking and hinting and eventually begging my label for the whole year I was making the album. I was influenced by a lot of her music and was desperate to work with her. As far as I'm aware, nobody could track her down."
Roberts also insisted that she wouldn't collaborate with just one member of Girls Aloud, adding: "I don't think we'd want to leave the other ones out. The rest would be saying, 'Why didn't you choose me?!' We couldn't do that to each other, we're a five."
> Read Digital Spy's interview with Nicola Roberts
Watch the music video for Nicola Roberts's debut single, 'Beat of my Drum', below: