larry nassar
© Reuters
Larry Nassar, a former team USA Gymnastics doctor.
The US Department of Justice issued a report Wednesday lambasting the FBI's handling of their probe into the former US Gymnastics physician Larry Nassar, who sexually abused hundreds of young athletes over the course of decades.

The DOJ's inspector general Michael Horowitz wrote in the 119-page report the FBI's Indianapolis field office mishandled the sexual abuse allegations from the very beginning and top brass at the office violated ethics rules and made false statements during the probe.

The long-awaited watchdog report said the FBI didn't treat the case with the "utmost seriousness and urgency" it deserved while the FBI acquiesced the conduct was "inexcusable and a discredit" to the country's premier law enforcement agency.

Horowitz's probe was sparked when the FBI was accused of failing to promptly respond to allegations first made in 2015 and outlines a series of missteps that occurred throughout the duration of the investigation.

When USA Gymnastics conducted its own internal look into complaints made against Nassar by at least 40 girls and women, they reported it to the FBI but it took months for the bureau to open a formal probe into the sicko doctor.

Horowitz's office revealed that "despite the extraordinary serious nature" of the allegations against the longtime physician, FBI investigators didn't respond with the "utmost seriousness and urgency" that the case "deserved and required."

When they finally did respond to the allegations, they repeatedly bungled the probe and made "numerous and fundamental errors" that violated internal policies.

The failures included only interviewing one of three athletes with allegations, even though the other two said they were available to meet, and failing to take responsibility for the errors and giving incomplete and inaccurate information when the probe came under internal scrutiny.

"The actions and inactions of certain FBI employees described in the Report are inexcusable and a discredit to this organization," the FBI said in response, adding the missteps "should not have happened."

"The FBI has taken affirmative steps to ensure and has confirmed that those responsible for the misconduct and breach of trust no longer work FBI matters," the statement continued.

"We will take all necessary steps to ensure that the failures of the employees outlined in the Report do not happen again."

The serial sexual abuser is currently serving a decades long prison sentence after he was charged in 2016 with federal child pornography and sexual abuse offenses and found guilty in 2017 during three separate trials.

He was convicted of sexually abusing hundreds of young girls under the guise of medical treatment when he worked for Michigan State and USA Gymnastics, the schoolhouse for future Olympians.

The inspector general's probe came after more than 60 witnesses, including victims, parents, prosecutors and former and current FBI employees, were interviewed.