A long-gestating biopic about Nina Simone continues to hit the wrong note with fans of the legendary American singer and civil rights activist dubbed the High Priestess of Soul. 

Producers of Nina, directed by Cynthia Mort, unveiled a trailer for the drama on Wednesday, with a chorus of online criticism greeting the film teaser's introduction.

Can't see the trailer? Click here 

Mort first optioned Simone's life story in 2005 and, at one point, Mary J. Blige had been attached to star. However, the R&B singer ultimately withdrew from the film, reportedly due to production delays.

When Zoe Saldana was subsequently tapped as the lead in 2012, Nina was widely blasted as an example of Hollywood "lightwashing" (casting a lighter-skinned performer under the belief that it will be more palatable to audiences).

Nina, which explores the final decade of the singer-songwriter's life and her return to the spotlight after struggles with addiction and her health, co-stars David Oyelowo as Simone's nurse-turned-manager Clifton Henderson. 

'I've never changed my hair. I've never changed my colour, I have always been proud of myself, and my fans are proud of me for remaining the way I've always been.' - Nina Simone

Many objected to the film's casting of the petite, light-skinned Afro-Latina actress as Simone, the outspoken figure who was unapologetic about her dark complexion, natural hair, full lips and wide nose and the artist who penned Four Women, which explores the experiences of black women of different skin tones.

"I've never changed my hair. I've never changed my colour, I have always been proud of myself, and my fans are proud of me for remaining the way I've always been," Simone told an interviewer in one of her most cited quotes.

"My mother was raised at a time when she was told her nose was too wide, her skin was too dark," the singer's daughter, Lisa Simone Kelly, told the New York Times in 2012. 

She also took issue with the film's creative licence in portraying her mother's relationship with Henderson as romantic, when in reality he was gay, she noted. Henderson died in 2006.

Trailer sparks fresh outrage

American actresses Viola Davis, Adepero Oduye, Danai Gurira and singer India Arie are among those who have been touted by many as more suitable picks.

The film's debut was further delayed when, in 2014, director Mort sued the production company behind the movie, alleging that she was cut out of key decisions, leaving her unhappy to be associated with the production.

With Wednesday's introduction of Nina's trailer, which shows Saldana wearing facial prosthetics and her complexion darkened with make-up, the earlier uproar has returned.

Simone's family and estate have also criticized the project, for which they were not consulted. Instead, Simone Kelly, the singer's daughter, participated with filmmaker Liz Garbus for the 2015 Netflix documentary What Happened, Miss Simone? — among Sunday's nominees for best doc feature at the Oscars.

Nina is set for release in all formats — in theatres, digital HD and video-on-demand — on April 22.