The singer-and-actress will receive the coveted honour at the Californian event in January in recognition for her portrayal of a dowdy social worker in 'Precious'.

Festival chairman Harold Matzner said: 'We're delighted to be able to present the Breakthrough Performance Award to the extraordinary, very beautiful and versatile Mariah Carey, who, in a critically acclaimed role, completely transformed herself from a glamorous music icon to a forthright social worker for the role of Ms. Weiss in Precious.'

Previous winners of the prize include Jennifer Hudson, Marion Cotillard and Freida Pinto, who all went on to win an Oscar for their performances.

Meanwhile, it has been claimed Mariah insisted on bringing her own toilet paper to a TV appearance.

The 'I Want To Know What Love Is' singer amazed presenters of UK TV show 'GMTV' with her diva-like antics, which also included being lowered onto a sofa by two people, with more members of her entourage being placed in the studio to check camera angles.

'GMTV' host Kate Garraway revealed in her column in New! Magazine: 'I've heard a lot of rumours about Mariah being a diva over the years and it turns out it's all true!

'While Mariah was very nice, the amount of people she had in her entourage was hilarious. They outnumbered the entire 'GMTV' crew! She had two people to lower her on to the sofa, in case her dress got crushed, one person to walk in front of her backwards at all times in case she fell over and several people behind the camera making sure she was going to be filmed from the right angle.

'Have you ever heard anything like it? Oh, and she brought her own toilet roll as well.'