McKayla Maroney
McKayla Maroney of USA gets ready to compete in the Womens Vault Qualification on Day Three of the Artistic Gymnastics World Championships Belgium 2013 held at the Antwerp Sports Palace on October 2, 2013 in Antwerpen, Belgium Dean Mouhtaropoulos/Getty Images

Olympic medalist McKayla Maroney says she was molested by former USA Gymnastics team doctor Larry Nassar from the time she was 13 to her retirement from the sport last year.

The 21-year-old posted a lengthy statement on Twitter on Wednesday that detailed the allegations of abuse.

She says the abuse began at one of her first team training camps and also occurred before events at the 2012 Olympics. She and her teammates won gold for the U.S. in London and Maroney took an individual silver medal on the vault.

Nassar is in jail in Michigan awaiting sentencing after pleading guilty to possession of child pornography.

He also is awaiting trial on separate criminal sexual conduct charges and has been sued by more than 125 women alleging abuse.

Attorneys for Nassar had no comment. USA Gymnastics also had no immediate comment.

Larry Nassar
Larry Nassar's mug shot Michigan Attorney General's office