By Jill Serjeant

(Reuters) - The American Film Institute has called off a Los Angeles screening of slavery movie "The Birth of a Nation" amid controversy over an old rape case involving the film's director just as Hollywood's awards season swings into gear.

The screening, scheduled for Friday at the AFI, was to be followed by a question and answer session with director Nate Parker in what would have been Parker's first public event since it emerged last week that the accuser in his 1999 rape trial and acquittal committed suicide in 2012.

Parker, 36, was little known before writing, directing and starring in the film which wowed audiences at the Sundance Film Festival in January and was seen as a strong 2017 Oscar contender. It tells the story of Nat Turner, who led a slave rebellion in Virginia in 1831.

Movie studio Fox Searchlight has said it stands by the movie, which will get its international premiere at the Toronto Film Festival in September, despite speculation in Hollywood that the rape case will affect the film's marketing and jeopardize Oscar chances.

The AFI said that its dean, Jan Schuette, told students on Tuesday that the Friday screening had been postponed until an unspecified date because of the "many different passionate points of view about the screening" he had received.

"I believe it is essential that we discuss these issues together - messenger and message, gender, race and more - before we see the film," Schuette wrote in a message to students.

Although Parker said last week that the 1999 incident was "a very painful moment in my life," details of the case have set off a fierce debate in Hollywood, the black community and among women's groups about whether it is possible to separate art from the artist.

Civil rights activist Al Sharpton and singer Harry Belafonte have defended the film, suggesting some sections of the media are using the rape case to discredit a powerful story about slave resistance.

The Hollywood Reporter on Wednesday quoted some members of the Academy of Motion Picture Arts and Sciences, which votes for the Oscars, as saying the film had become problematic.

"The Birth of a Nation" is scheduled to open in U.S. movie theaters on Oct. 7. Oscar nominations are announced on Jan. 24.

The film shares a title with the 1915 D.W. Griffith epic drama, but is a very different story and is told from an African-American perspective.

(Reporting by Jill Serjeant in New York; Editing by Matthew Lewis)