WASHINGTON • Olympic gold medallist McKayla Maroney said she was sexually abused by the team doctor who is already facing criminal charges for molesting other American gymnasts.

The 21-year-old said in a statement on Twitter that Lawrence Nassar began molesting her at the age of 13 and it continued throughout her gymnastics career.

"Dr Nassar told me that I was receiving 'medically necessary treatment that he had been performing on patients for over 30 years'," she wrote.

"It started when I was 13 years old, at one of my first national team training camps, in Texas, and it didn't end until I left the sport.

"It seemed whenever and wherever this man could find the chance, I was 'treated'."

She added that the abuse even occurred during the London 2012 Olympics, where Maroney was a member of the "Fierce Five" squad which won the team gold medal.

"It happened in London before my team and I won the gold medal, and it happened before I won my silver (vault)," she wrote.

"For me, the scariest night of my life happened when I was 15 years old. I had flown all day and night with the team to get to Tokyo (for the 2011 World Championships).

"He'd given me a sleeping pill for the flight, and the next thing I know, I was all alone with him in his hotel room getting a 'treatment'.

"I thought I was going to die that night."

Nassar is in jail in Michigan, facing 22 counts of first-degree criminal sexual conduct involving at least seven other individuals.

Nassar, who has pleaded guilty to possession of child pornography, is awaiting trial and he has been sued by more than 125 women accusing him of sexual abuse.

He has pleaded not guilty to the assault charges, and dozens of civil suits filed against him in Michigan are currently in mediation.

Maroney is the most high-profile US gymnast to have spoken out.

"Wherever there is a position of power, there seems to be a potential for abuse," she said.

"I had a dream to go to the Olympics, and the things that I had to endure to get there were unnecessary and disgusting."

More than 350 gymnasts were reportedly abused according to an investigation by The Indianapolis Star.

In a statement, USA Gymnastics praised the "courage" of Maroney and others, "who have come forward to share their personal experiences with sexual abuse".

"Because of their strength in coming forward, predators can be held accountable for their actions," said the governing body.

"We, like so many others, are outraged and disgusted by the conduct of which Larry Nassar is accused.

"We are sorry that any athlete has been harmed during her or his gymnastics career."

USA Gymnastics added that it was "strengthening and enhancing our policies and procedures regarding abuse" and was committed to working to "keep our athletes as safe as possible".

NYTIMES, AGENCE FRANCE-PRESSE