The Trump administration is investigating the FBI into how it handled sexual-abuse allegations against former U.S. gymnastic national-team doctor Larry Nassar following accusations that agents failed to respond to claims made by gymnasts in 2015, the Wall Street Journal reported.

The Department of Justice's inspector general’s probe stems from an internal FBI review into the bureau’s handling of the allegations against Nassar. It reportedly took at least nine months before the FBI officially opened a probe in the disgraced doctor.

Nassar pleaded guilty last year to state sexual-abuse and federal child-pornography charges, though none of the charges included national-team gymnasts’ 2015 allegations, and was sentenced in January to 60 years in federal prison.

The FBI will also face scrutiny from other bodies of government, including Congress and its Senate Judiciary and Senate Commerce committees, which urged in a letter to FBI Director Christopher Wray to provide information and materials related to the bureau’s handling of the allegations.

The DOJ probe will focus on how numerous FBI officials acted on or potentially failed to act on the allegations raised by gymnasts against Nassar and why it took at least nine months until a formal investigation into Nassar was opened.

According to the Journal, the DOJ investigators have already interviewed several people, including athletes and gymnastics officials, as part of their probe efforts. The investigation could potentially lead to criminal charges or disciplinary action.

The investigators are looking into the Indianapolis FBI office’s 2015 handling of the gymnasts’ allegations, the newspaper reported. Former Olympian McKayla Maroney reportedly spoke with a local bureau agent over the phone, rather than in person, concerning the allegations against Nassar, yet the interview didn’t lead to the opening of a formal investigation.

This prompted the DOJ to seek for correspondence between former USA Gymnastics Chief Executive Steve Penny and officials at FBI field offices in Indianapolis and Los Angeles. Penny’s correspondence with the former special agent in charge of the Indianapolis office, W. Jay Abbott, are also being looked at.

Abbott previously told the New York Times that the allegations against Nassar were complicated due to the sensitivity of child sexual-abuse allegations and because “there was a vigorous debate about whether” Nassar’s techniques constituted “a legitimate medical procedure,” as Nassar said himself.