Four-time Olympic champion Simone Biles has said she was sexually abused by Team USA's former gymnastics doctor Larry Nassar.
Nassar is serving 60 years in prison for having child sex abuse images on his computer and is awaiting sentence after admitting assaulting female gymnasts.
Biles, who won team, all-around, vault and floor exercise gold medals at Rio 2016, has said she was also abused by Nassar.
The 20-year-old Biles posted a statement on Twitter that read: "Most of you know me as a happy, giggly, and energetic girl. But lately... I've felt a bit broken and the more I try to shut off the voice in my head the louder it screams.
"I am not afraid to tell my story anymore. I too am one of the many survivors that was sexually abused by Larry Nassar."
Three former US Olympians have accused Nassar of sexual abuse, including Gabby Douglas, Aly Raisman and McKayla Maroney.
Biles continued: "It is not normal to receive any type of treatment from a trusted team physician and refer to it horrifyingly as the 'special' treatment. This behavior is completely unacceptable, disgusting, and abusive, especially from someone whom I was TOLD to trust.
"For too long I've asked myself, 'Was I too naive? Was it my fault?' I now know the answer to those questions. No. No, it was not my fault. No, I will not and should not carry the guilt that belongs to Larry Nassar, the USAG, and others.
"It is impossibly difficult to relive these experiences and it breaks my heart even more to think that as I work towards my dream of competing in Tokyo 2020, I will have to continually return to the same training facility where I was abused."
The 54-year-old Nassar was involved with America's world-beating gymnastics programme from the 1980s until July 2015, when the sport's national governing body sacked him.
More than 130 women have filed civil lawsuits against him alleging abuse.