The FBI is under investigation for how it handled allegations of sexual abuse against sicko sports doctor Larry Nassar, according to a report.

Justice Department inspectors are looking into what actions the FBI took after they received sexual abuse complaints against the former USA Gymnastics doctor, according to the Wall Street Journal.

USA Gymnastics passed along complaints from athletes to the FBI field office in Indianapolis in July 2015.

But the FBI didn’t open a formal investigation into the now-disgraced doc until almost a year later, in the spring of 2016 in Los Angeles.

US investigators are particularly interested in how FBI agents in Indianapolis dealt with the gymnasts, according to the WSJ report.

Around September 2015, an agent in the Indianapolis field office spoke with former Olympian McKayla Maroney over the phone — instead of in person — about her allegations against Nassar, and the conversation didn’t lead to an investigation.

Later that fall, the Indianapolis office referred the matter to the FBI office in Detroit, where Nassar lived —but they didn’t open an investigation either.

DOJ investigators have already interviewed several people, including athletes and gymnastics officials, the report said. They’ve also sought out correspondence between former USA Gymnastics chief executive Steve Penny and officials at FBI field offices in Indianapolis and Los Angeles.

The Justice Department probe could lead to disciplinary actions and criminal charges, according to the report.

A spokesman for the Inspector General’s Office declined to comment. The FBI has previously said it was “reviewing our role in the investigation” of Nassar and declined to comment to the WSJ further.

Nassar pleaded guilty last year to federal child pornography charges and state sexual abuse charges in Michigan and was sentenced to 60 years in federal prison in January. He was sentenced to 40 to 125 years for the sex abuse charges in February. None of the charges stemmed from the US gymnasts’ allegations.