Updated

Larry Nassar, the disgraced former sports doctor who was convicted of sexually abusing female gymnasts, was stabbed during an altercation with another inmate at a Florida federal prison, according to sources familiar with the matter.

The attack occurred Sunday at United States Penitentiary Coleman in Sumterville, sources told Fox News. The Associated Press first reported about the incident.

Nassar was stabbed multiple times, according to a person familiar with the attack. Joe Rojas, a current and longtime employee of the prison and current president of the local union, told Fox News that Nassar was stabbed twice in the neck, twice in the back and six times in the chest.

Rojas also said that it was his understanding that Nassar suffered a collapsed lung and that he was in stable condition. He also added he believes the prison is understaffed.

Federal officials confirmed to Fox News Digital a stabbing occurred at around 2:35 p.m. ET on Sunday and that staff members initiated life-saving measures. An inmate was taken to a local hospital for further treatment. Officials didn't identify the victim or the assailant.

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Former team USA Gymnastics doctor Larry Nassar pleaded guilty to sexual assault charges

Larry Nassar, a former USA Gymnastics doctor who pleaded guilty in November 2017 to sexual assault charges, stands in court during his sentencing hearing in Eaton County Court in Charlotte, Michigan, on Feb. 5, 2018. (Reuters)

Officials said an investigation is ongoing. The prison currently houses more than 1,200 male offenders.

Nassar is serving decades in prison for sexually assaulting gymnasts, including Olympic medalists. He admitted sexually assaulting athletes when he worked at Michigan State University and USA Gymnastics.

He also pleaded guilty to possessing child pornography.

During victim impact statements in 2019, several athletes testified that over the course of Nassar’s more than two decades of sexual abuse, they had told coaches and trainers and other adults what was occurring, but it went unreported.

Nassar is likely to spend the rest of his life behind bars.

More than 150 victims spoke or submitted statements during the seven-day hearing, including Simone Biles. The women sought more than $1 billion from the federal government over the FBI’s failure to stop Nassar when agents became aware of the allegations against him in 2015.

Nassar in Michigan

Larry Nassar (AP Photo / Paul Sancya / File)

FLASHBACK: LARRY NASSAR VICTIMS, INCLUDING OLYMPIANS, SEEK OVER $1B IN CLAIMS AGAINST FBI FOR INVESTIGATION FAILURES

A final appeal from Nassar was rejected by the Michigan Supreme Court last month. Attorneys for Nassar said he was treated unfairly in 2018 and deserved a new hearing based on the judge calling him a "monster," among other remarks.

"I just signed your death warrant," Ingham County Judge Rosemarie Aquilina said of Nassar’s 40-year sentence.

While the Michigan Supreme Court said it had concerns over the judge’s conduct, officials noted Aquilina stuck to the sentencing agreement worked out by the lawyers on the case.

Simone Biles Congress

More than 150 victims spoke or submitted statements during the seven-day hearing, including Simone Biles. (AP Newsroom / File)

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"We decline to expend additional judicial resources and further subject the victims in this case to additional trauma where the questions at hand present nothing more than an academic exercise," the court said.

The Associated Press contributed to this report.