Frazer Harrison/Getty
Sacheen Littlefeather‘s legacy has been called into question by her family.
After the actress, model and Native American civil rights activist died at age 75 earlier this month, Littlefeather’s two sisters claimed that she lied about her indigenous ancestry and was previously known by the family as “Deb” in a bombshell interview with the San Francisco Chronicle.
“It’s a lie,” Trudy Orlandi said of her sister. “My father was who he was. His family came from Mexico. And my dad was born in Oxnard.”
RELATED: Sacheen Littlefeather, Native American Activist Who Refused Oscar for Marlon Brando, Dead at 75
Littlefeather’s other sister Rosalind Cruz added: “It is a fraud. It’s disgusting to the heritage of the tribal people. And it’s just … insulting to my parents.”
Littlefeather, who claimed to belong to the White Mountain Apache and Yaqui tribes on her father’s side, rose to infamy in 1973 at the 45th Academy Awards, where she turned down the Oscar for Best Actor on behalf of Marlon Brando, in protest of the film industry’s treatment of Native Americans.
Michael Ochs Archvies/Getty
In addition to being threatened with arrest if her speech went over 60 seconds, as well as alleged physical violence from John Wayne, who she claimed attempted to storm the stage, Littlefeather faced public mockery over the years for the historic television moment.
In 1990, Littlefeather told PEOPLE of the fallout she faced in response to her Oscars moment. “I’m officially retired as the refuser of Academy Awards,” she said, noting that the speech killed her career in Hollywood.
“I went up there thinking I could make a difference,” explained Littlefeather. “I was very naive. I told people about oppression. They said, ‘You’re ruining our evening.'”
The Academy of Motion Picture Arts and Sciences offered Littlefeather an apology in August for the mistreatment she faced nearly 50 years before. She accepted the apology and was honored onstage during an event last month at the Academy Museum of Motion Pictures in Los Angeles.
Paul Chinn/The San Francisco Chronicle via Getty
Littlefeather died from metastasized breast cancer on Sunday, Oct. 2 at her home in Marin County, Calif., surrounded by friends and family.
“Littlefeather dedicated her life to the health and wellness of Native people everywhere,” read a press release at the time. “She was known for her sense of humor, quick wit, and fierce advocacy for Native American and Indigenous communities.”
Cruz and Orlandi came forward to restore their parents’ reputation, as Littlefeather is “being venerated as a saint” after claiming her father was a violent alcoholic who abused them and their white mother.
RELATED VIDEO: Sacheen Littlefeather Says 1973 John Wayne Incident Was ‘Most Violent Moment’ in Oscars History
Orlandi said it “infuriates me” that she lied about having a violent and impoverished upbringing, which she actually stole from their father’s childhood experience.
“My father was deaf, and he had lost his hearing at 9 years old through meningitis,” Cruz said. “He was born into poverty. His father, George Cruz, was an alcoholic who was violent and used to beat him. And he was passed to foster homes and family. But my sister Sacheen took what happened to him.”
Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
The Chronicle found family records in Mexico going back to 1850, everyone identified as either white or Mexican since 1880. Additionally, the White Mountain Apache tribe had no enrollment records for Littlefeather or any family members, living or dead.
Orlandi added: “The best way that I could think of summing up my sister is that she created a fantasy. She lived in a fantasy, and she died in a fantasy.”
