Nicole Kidman famously won her Oscar "by a nose" - but don't expect Mariah Carey to let a fake schnoz come between her and her public.

A source tells us that her character in "Tennessee," produced by Lee Daniels, had to be significantly de-glammed - which didn't go down too well.

"Mariah is the nicest person to work with; everyone loves her," says the snitch. "But she was uncomfortable being uglied up for the part."

Carey plays a Southern waitress who sets off with two brothers in search of their father. While she consented to cornrows, she passed on the fake nose and bushy eyebrows that had been conceived for the part.

"When she saw the nose, she called her people and decided against it," says the source. "She was not a diva about it, but she did seem very insecure about her appearance."

(A source close to Daniels denied the production had suggested she wear a fake nose.)