Simone Biles says she was abused by US team doctor Larry Nassar

Four-time Olympic champion Simone Biles says she was sexually abused by former USA gymnastics team doctor Larry Nassar.

Nassar was jailed in December 2017 for 60 years for possession of child abuse images and is also awaiting sentencing after admitting to assaulting seven female gymnasts.

The 54-year-old could be jailed for life under the sexual assault charges, to which he pleaded guilty.

Biles, 20, said she had been debating whether or not to go public with her story as she continues to train for Tokyo 2020.

The four-time Olympic champion wrote on Twitter: "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."

She added: "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, USA Gymnastics 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 to have to continually return to the same training facility where I was abused."