Disgraced sports doctor Larry Nassar, who was convicted of sexually abusing female gymnasts, was stabbed multiple times during an altercation with another incarcerated person at a federal prison in Florida.

Two people familiar with the matter told The Associated Press that the attack happened on Sunday at United States Penitentiary Coleman in Florida. They said he was in stable condition on Monday.

One of them said he had been stabbed in the back and in the chest.

They were not authorized to publicly discuss details of the attack or the ongoing investigation and spoke on the condition of anonymity.

Nassar was sentenced to decades in prison for sexually assaulting gymnasts, including Olympic medalists.

Nassar is serving decades in prison for convictions in state and federal courts. He admitted sexually assaulting athletes when he worked at Michigan State University and USA Gymnastics, which trains Olympians. Separately, Nassar pleaded guilty to possessing child pornography.

During victim impact statements in 2018, several athletes testified that over the course of Nassar's more than two decades of sexual abuse they had told adults what was happening, including coaches and athletic trainers, but that it went unreported.