R&B star India Arie has slammed Zoe Saldana's casting as jazz legend Nina Simone, branding the move "ridiculous".

Cynthia Mort, director of upcoming biopic Nina, has been forced to defend her choice of Saldana for the title role following a wave of criticism, including from the late singer's daughter Simone Kelly.

Now Arie has waded into the controversy after seeing photographs of the Avatar actress wearing prosthetics while filming the movie, insisting Saldana looks "weird".

In a message posted on NinaSimone.com, she writes, "I saw the images of Zoe Saldana as Nina Simone... and I think they are ridiculous! Yes there should be a movie made, and yes they should have chosen someone who Looks like Nina Simone, especially since her race played such a pivotal role in who, what and why, she was.

"That aside for a second, this just looks WEIRD, it looks like a person in Black(er) face with a fake nose... Really?!!!! Does not the one Nina Simone's (sic) legacy deserve better than this?...

"But these images... just make me feel... Sad. Not because I want to play Nina Simone but because it feels out of place with what Nina Simone means in an African American historical context!!!!"