A series of institutions, including the US Olympic Committee and FBI, “fundamentally failed” to protect young athletes from the serial sexual abuser Larry Nassar, according to a congressional report.

Nassar, a former doctor for Michigan State University and USA Gymnastics, was given an effective life sentence last year for abusing dozens of young gymnasts in his care. The Senate commerce subcommittee on manufacturing, trade and consumer protection has conducted an 18-month investigation into the Nassar case. It found multiple organisations failed to act on credible reports that Nassar was abusing athletes.

“Whether it was a criminal cover-up remains to be proven, but it was a cover-up in spirit,” Senator Richard Blumenthal told NBC News on Tuesday.

Senator Jerry Moran, the chair of the subcommittee, was similarly scathing. “Terrible things happened,” he told NBC News. “In many instances they were reported and, almost without exception, the people that they were reported to didn’t respond.”

According to the report, which was obtained by NBC before publication on Tuesday, the USOC, USA Gymnastics, FBI and MSU all “had opportunities to stop Nassar but failed to do so.”

High-profile gymnasts, including Olympic champions Simone Biles and Aly Raisman, have said they were abused by Nassar. “The Olympic-related organization’s ability to identify and prevent abuse was inadequate,” the report says. “As a result, hundreds of women and girls were sexually abused by Larry Nassar.”

An @NBCNews exclusive: For 421 days, the FBI, the US Olympic Committee and USA Gymnastics all failed to act or even warn Michigan State University, where Dr. Larry Nassar worked, that he was sexually abusing athletes, @tomcostellonbc reports pic.twitter.com/d9K1vNAOSQ — TODAY (@TODAYshow) July 30, 2019

The report also details failings by the FBI. The Bureau opened an investigation into Nassar in July 2015 after receiving credible reports of abuse. But, the report says, the FBI “did not stop Nassar from seeing patients or protect those in harm’s way” for more than a year as the investigation was moved between different offices.

On Tuesday, Blumenthal said Nassar could not have continued his abuse without the failings of others. “Larry Nassar…was far from a lone wolf,” said Blumenthal. “He was enabled by others and if they lied about it and if they obstructed the investigation, if they destroyed documents then they should be held accountable.”

Legislation arising from the investigation would allow Congress to fire the board of the USOC and USA Gymnastics if necessary. The bill, which will be introduced on Tuesday, would also quadruple the money provided to the US Center for SafeSport, which is designed to protect young athletes.