The FBI made “fundamental” errors in investigating sexual abuse allegations against former USA Gymnastics national team doctor Larry Nassar and did not treat the case with the “utmost seriousness,” the Justice Department’s inspector general said on Wednesday.

More athletes said they were molested before the FBI swung into action.

The FBI acknowledged conduct that was “inexcusable and a discredit” to America’s premier law enforcement agency and all.

The long-awaited watchdog report raises troubling questions about how the department and the FBI handled the case and it highlights major missteps at the FBI between the time the allegations were first reported and Nassar’s arrest.

The inspector general’s investigation was spurred by allegations that the FBI failed to promptly address complaints made in 2015 against Nassar. USA Gymnastics had conducted its own internal investigation and then the organization’s then-president, Stephen Penny, reported the allegations to the FBI’s field office in Indianapolis. But it took months before the bureau opened a formal investigation.

At least 40 girls and women said they were molested over a 14-month period while the FBI was aware of other sexual abuse allegations involving Nassar. Officials at USA Gymnastics also contacted FBI officials in Los Angeles in May 2016 after eight months of inactivity from agents in Indianapolis.

The inspector general’s office found that “despite the extraordinarily serious nature” of the claims against Nassar, FBI officials in Indianapolis did not respond with the “utmost seriousness and urgency that the allegations deserved and required.”

When they did respond, the report said, FBI officials made “numerous and fundamental errors” and also violated bureau policies. Among the missteps was a failure to conduct any investigative activity until more than a month after a meeting with USA Gymnastics. Agents interviewed by phone one of three athletes, but never spoke with two other gymnasts despite being told they were available to meet.

The watchdog investigation also found that when the FBI’s Indianapolis field office’s handling of the matter came under scrutiny, officials there did not take any responsibility for the missteps and gave incomplete and inaccurate information to internal FBI inquiries to make it look like they had been diligent in their investigation.

The FBI rebuked its own employees who failed to act in the case and said it “should not have happened.”

“The actions and inactions of certain FBI employees described in the Report are inexcusable and a discredit to this organization,” the agency said in a statement.

The inspector general interviewed an FBI supervisory special agent last September who said the original allegations reported by Penny and USA Gymnastics were “very vague” and who questioned Penny’s credibility.

The FBI said the supervisory special agent “violated multiple policies” and that the agency took immediate action when it learned that the agent did not properly document the sexual abuse complaints, had mishandled evidence, and failed to report abuse.

Nassar was ultimately charged in 2016 with federal child pornography offenses and sexual abuse charges in Michigan.

(With inputs from AP)