LARRY Nassar, the disgraced USA Gymnastics ex-doctor who was convicted of sexually abusing young female gymnasts, has been stabbed by another inmate in prison and was in stable condition on Monday, U.S. media reported.

The Federal Bureau of Prisons confirmed that an inmate at the U.S. Penitentiary Coleman in Florida was assaulted on Sunday afternoon, but declined to identify the prisoner over privacy and security concerns.

"Responding staff immediately initiated life-saving measures," bureau spokesperson Benjamin O'Cone said in a statement. "The inmate was transported by (emergency personnel) to a local hospital for further treatment and evaluation."

The FBI was notified of the incident, and an internal investigation is ongoing, O'Cone added. No other staff or inmates were injured, he said.

Nassar, who is serving a decades-long sentence following his 2018 conviction, was stabbed in the back and chest during an argument on Sunday, the Associated Press reported, citing a person familiar with the matter. He was in stable condition, the AP and ABC reported.

Nassar was sentenced to up to 175 years in prison for sexually abusing young female gymnasts who were entrusted to his care. Those gymnasts include Olympic gold medalists Simone Biles, Aly Raisman and McKayla Maroney.