Gymnastics: Olympic superstar Simone Biles slams US Gymnastics, FBI for sexual misconduct oversight

Olympic gymnast Simone Biles has blasted USA Gymnastics and the FBI in blunt, tearful testimony for standing by, while Larry Nassar abused her and hundreds of other athletes.

"We have been failed and we deserve answers," Biles has told the Senate Judiciary Committee, where she appeared with three other athletes, Aly Raisman, McKayla Maroney and Maggie Nichols.

"It really feels like the FBI turned a blind eye to us," she says.

The hearing follows a scathing reporter from Justice Department inspector general Michael Horowitz, which blasted the FBI for botching its investigation with a series of errors that allowed the abuse to continue for months.

Horowitz will also testify, as will FBI director Chris Wray, who is expected to face sharp bipartisan questioning about why the agents who botched the probe were never prosecuted for their misconduct.

"It is not only that the FBI failed to do its job, systematically and repeatedly, it is also the cover-up that occurred when FBI agents made materially false statements and deceptive omissions," Senator Richard Blumenthal says, adding that the Justice Department has declined to prosecute the agents.

"My hope is that the Department of Justice, which was invited and has declined to appear, will match your courage by explaining why those lies by FBI agents did not lead to criminal prosecution."

The FBI's investigation into Nassar started in July 2015, after USA Gymnastics president and chief executive Stephen Penny reported the allegations to the FBI's Indianapolis field office, and provided agents with the names of three victims willing to be interviewed.

That office, then led by special agent in charge W Jay Abbott, did not formally open an investigation.

The FBI only interviewed one witness months later, in September 2015, and failed to formally document that interview in an official report known as a '302' until February 2017 - well after the FBI had arrested Nassar on charges of possessing sexually explicit images of children in December 2016.

When the interview was finally documented in 2017 by an unnamed supervisory special agent, the report was filled with "materially false information and omitted material information", Horowitz's report determined.

The office also failed to share the allegations with state or local law enforcement agencies.

Maroney recalls how, in 2015, she spent three hours on the phone, telling the FBI the details of her story that her own mother had not even heard, including accounts of sexual abuse she endured from Nassar during the Olympic games in London, described him as "more of a pedophile" than a doctor.

She says the Justice Department inspector general did not reveal what the FBI actually did with the information she provided until July this year, failing to document it for a year and a half and misrepresenting what she told them about her experiences.

"Not only did the FBI not report my abuse, but when they eventually documented my report 17 months later, they made entirely false claims about what I said," Maroney says, with anger in her voice.

Horowitz also says that Abbott, who retired from the FBI in 2018, also violated the FBI's conflict-of-interest policy by discussing a possible job with the US Olympic Committee, while he was involved with the Nassar investigation.

Neither Abbott nor the other unnamed supervisory special agent who botched the Nassar probe were prosecuted for their actions.

The FBI previously called Abbott's behavior "appalling" and said the supervisory special agent remains with the FBI, but is no longer a supervisor and is "not working on any more FBI matters".

An attorney for Abbott previously said he was thankful to prosecutors for bringing Nassar to justice.

In 2017, Nassar, who had been the main doctor for Olympic gymnasts, was sentenced to 60 years in prison in federal court on charges of possessing child sex abuse material.

The following year, he was also sentenced up to 175 years and up to 125 years respectively in two separate Michigan courts for molesting female gymnasts under his care. Prosecutors estimate he sexually assaulted hundreds of women.