Congress: FBI, Olympic Committee covered up Larry Nassar's abuse of athletes for more than a year

A Congressional investigation has found that the FBI, the U.S. Olympic Committee and USA Gymnastics were all aware that team doctor Larry Nassar was sexually abusing athletes, but sat on the information for more than a year before taking action in what one senator is calling a cover-up.

What are the details?

NBC News was given exclusive access to the report published by the Senate Commerce Subcommittee on Manufacturing, Trade, and Consumer Protection, which revealed that between the summer of 2015 and September 2016 — for 421 days — the organizations "knowingly concealed abuse by Nassar, leading to the abuse of dozens of additional amateur athletes."

Sens. Jerry Moran (R-Kan.) and Richard Blumenthal (D-Conn.) sat down with NBC to discuss their subcommittee's findings, and plan to put forth legislation aimed at preventing future abuse. Blumenthal told the outlet, "Whether it was a criminal cover-up remains to be proven, but it was a cover-up in spirit."

"Terrible things happened," Moran added. "In many instances they were reported and, almost without exception, the people that they were reported to didn't respond."

The organizations also failed to even warn Nassar's employer at the time, Michigan State University, of the allegations against the doctor who abused hundreds of young girls and women over the span of two decades.

Nassar pleaded guilty to sexually abusing 10 minors in Michigan court in January 2018, NBC News reported. He is serving a prison sentence of up to 175 years and is expected to be behind bars for the rest of his life.

Anything else?

It's no surprise that Congress found USA Gymnastics covered up Nassar's abuse — that fact was established well over a year ago, and the organization has since filed for bankruptcy. Yet the revelation that the FBI failed to act on the allegations is something new, and the legislation slated to be proposed Tuesday would reportedly grant Congress greater oversight in assuring the safety of American Olympic athletes.

What did the organizations say?

Li Li Leung, president and CEO of USA Gymnastics, said in a statement Tuesday that the organization had not yet seen the report or the proposed legislation, but it had "already made numerous changes designed to prevent the opportunity for abuse to occur. We have made it our top priority to become an athlete-centric organization that keeps athlete safety and well-being at the forefront of all that we do."

Leung said USA Gymnastics will implement "most of the recommendations made in an independent, investigative review of our safe sport policies and procedures."

U.S. Olympic Committee CEO Sarah Hirshland told NBC News on Tuesday that "increasing accountability" is central to the organization's ongoing reform. She also applauded Congress for the proposed legislation and said it is consistent with the Olympic Committee's approach.

The FBI declined to comment to NBC News and referred questions to the Department of Justice Office of the Inspector General.