Olympic gold medalist McKayla Maroney has joined the #MeToo movement, in which women speak out about sexual harassment and assault.
She claims she was assaulted by her doctor while on the Olympic squad, and that it began when she was just 13 years old.
The former gymnast was speaking out to show it was not just Hollywood that had a problem, in the wake of the Harvey Weinstein allegations.
In a statement posted to Twitter, the 21-year-old said she was molested by former USA Gymnastics team doctor Larry Nassar.
He is currently awaiting his sentence after pleading guilty to child pornography charges.#
Nassar is also awaiting trial on separate criminal sexual conduct charges and is being sued by over 125 women in civil court who claim he sexually assaulted them.
Ms Maroney wrote: "People should know that this is not just happening in Hollywood.
"It started when I was 13 years old, and it didn’t end until I left the sport".
She spoke of how he abused her: "Dr. Nassar told me that I was receiving 'medically necessary treatment that he had been performing on patients for over 30 years'.
"It seemed whenever and wherever this man could find the chance, I was 'treated'.
"It happened in London before my team and I won the gold medal, and It happened before I won my Silver."
The former gymnast, who is now pursuing a music career, said the worst abuse happened in 2011.
She alleged Nassar had given her a sleeping pill on a flight to Tokyo, and she didn't wake until she was in his hotel room, alone, where he was performing a 'treatment'.
"I thought I was going to die that night," she wrote.
She said that in order to stop this treatment of women happening, organisations need to be held to account and there should be a zero-tolerance policy towards these actions.
The former USA Gymnastics team doctor has pleaded not guilty to the assault charges and and the civil suits filed in Michigan.
In June, witnesses testified against the disgraced doctor, claiming he molested girls while pretending to provide medical care and helping spinal alignment.
Many alleged victims have spoken out against Nasser, including several Team USA gymnasts.
@McKaylaMaroney I'm so sorry this happened to you. I'm proud of you for speaking up and finding your voice. May you begin healing.— Dominique Moceanu (@Dmoceanu) October 18, 2017
Sydney Olympics bronze medalist Jamie Dantzscher told 60 Minutes in February that he gave similar invasive "treatments" to her.
USA Gymnastics said earlier this year it was "outraged that a physician would exploit his patients in the manner alleged", and described Nassar's behavior as "appalling and heartbreaking".
It added it had "cooperated fully with the FBI and other law enforcement agencies".