As the sentencing of the former USA Gymnastics team doctor starts in a Michigan courtroom, questions are being asked over how he was allowed to sexually abuse dozens of young athletes, including one of the stars of the 2016 Olympics, Simone Biles.

In November, Larry Nassar admitted to abusing gymnasts under the guise of administering medical treatment. Prosecutors are seeking a 40- to 125-year prison sentence.

The first witness in court on Tuesday was Kyle Stephens, who told the court she was abused by Nassar, a family friend, between the ages of six and 12. “I testified to let the world know that you are a repulsive liar,” Stephens said as she addressed Nassar, who sat with his head bowed. Stephens added that she had told her parents about Nassar’s abuse but he had convinced them she was lying.

“Perhaps you have figured it out by now, but little girls don’t stay little for ever,” Stephens said. “They grow into strong women that destroy your world.”

Why don't we care about the biggest sex abuse scandal in sports history? | Bryan Armen Graham Read more

Other women who appeared in court detailed the physical and mental pain caused by Nassar’s abuse. Donna Markham recounted how her daughter Chelsey had taken her own life years after Nassar had molested her. “It all started with him,” she said after describing Chelsey’s struggles with drug addiction.

On Monday, Biles became the latest gymnast to say she was molested by Nassar while under his care. “Most of you know me as a happy, giggly, and energetic girl,” the four-times Olympic gold medalist wrote on Twitter. “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.”

Play Video 1:42 'Little girls don't stay little forever': abuse victims confront Larry Nassar – video

Some of Biles’s fellow Olympic champions have said they were abused by Nassar, including Aly Raisman, McKayla Maroney and Gabby Douglas. Biles said she was encouraged to come forward after discovering what her fellow athletes had said.

“After hearing the brave stories of my friends and other survivors, I know that this horrific experience does not define me,” wrote the 20-year-old. “I am much more than this. I am unique, smart, talented, motivated, and passionate. I have promised myself that my story will be much greater than this.”

USA Gymnastics and Michigan State University, where Nassar ran a clinic and was a faculty member, have come under heavy criticism for their handling of the case. Four athletes told ESPN they had reported Nassar’s abuse to Michigan State in the late 1990s, while Nassar continued to see patients at MSU for 16 months after a criminal investigation into his actions was launched in July 2014. Raisman says she suffered abuse after that date. MSU has denied there was a cover-up.

Maroney filed a lawsuit against USA Gymnastics last month, alleging that officials paid her to sign a confidential financial settlement to remain silent on the abuse. ESPN also reported that Nassar did not leave his position at USA Gymnastics until months after allegations of abuse had been reported.

Biles also laid some blame on USA Gymnastics on Monday. “For too long I’ve asked myself, ‘Was I too naive? Was it my fault?’ I now know the answer to those questions,” she wrote. “No. No, it was not my fault. No, I will not and should not carry the guilt that belongs to Larry Nassar, USAG, and others.”

On Monday, USA Gymnastics offered support for Biles but did not comment on allegations it had failed its athletes. “USA Gymnastics is absolutely heartbroken, sorry and angry that Simone Biles or any of our athletes have been harmed by the horrific acts of Larry Nassar,” it said in a statement.

Nassar has already been sentenced to 60 years in prison in a separate case, regarding child abuse images.