Native American actress and activist Sacheen Littlefeather, who declined the best-actor award on behalf of Marlon Brando during an Oscars protest in 1973, has died aged 75, the motion picture Academy said on Monday.

Littlefeather, who the Hollywood Reporter said died at her home in California on Sunday surrounded by loved ones, was catapulted to fame when her friend Brando boycotted the 45th Oscars ceremony over what he viewed as the stereotypical portrayal of Native Americans in films and on television.

Taking to the stage in a traditional buckskin dress to refuse the Oscar — awarded for Brando's portrayal of Vito Corleone in "The Godfather" — in his stead, she gave a critical speech on the same issue, also drawing attention to a protest at Wounded Knee, South Dakota against the mistreatment of American Indians.

She was booed off for her remarks and boycotted by the film industry for decades.

This year Littlefeather, who had been diagnosed with breast cancer, received a belated apology letter from then-Academy president David Rubin, and last month the Academy Museum of Motion Pictures held an event in her honor.

"I was representing all indigenous voices out there, all indigenous people, because we have never been heard in that way before," she said, reflecting on what happened in 1973.