Lawrence G. Nassar, the doctor convicted of sexually abusing young female gymnasts, was stabbed multiple times in the chest, back and neck at the federal prison in Florida where he is serving a 60-year sentence, according to two people with knowledge of the situation.
Mr. Nassar, 59, is in stable condition after he was attacked by another inmate at the Federal Correctional Complex Coleman, a sprawling prison compound in Central Florida, they said.
It is not clear when the altercation took place or what prompted the attack. A spokeswoman for the Federal Bureau of Prisons, which manages the complex, did not immediately return a request for comment.
The episode adds to a long, troubled case of a once-prominent sports physician accused of molesting and assaulting dozens of young women and children, including athletes at Michigan State University, Olympians and members of the U.S. national gymnastics team — in the guise of providing treatment and examinations.
In a scathing 2021 report, the inspector general for the Justice Department found that the F.B.I. initially botched the investigation, allowing Mr. Nassar to assault more young women.
Mr. Nassar was convicted on federal charges in 2017. He was sentenced to an additional 40 to 125 years by a judge in Michigan a year later, after pleading guilty to three additional counts of sexual assault. A federal judge ordered that sentence to run concurrently and remanded him to federal custody.
The incident is also the latest in a series of suicides and violent attacks on some of the most notorious inmates in the chronically understaffed Federal Bureau of Prisons. Last month, Theodore J. Kaczynski, known as the Unabomber, who killed three people and injured 23 in a bombing spree from 1978 to 1995, died by suicide at a federal prison medical center in North Carolina.
In 2018, James Bulger, a gangster from Boston known as Whitey, was brutally beaten to death at a federal prison after he was transferred to a West Virginia prison in 2018 after a cascade of management failures and breaches of protocol left him unattended and vulnerable to attack, the inspector general found. A similar environment of dysfunction was pervasive at the Manhattan federal prison where the financier Jeffrey Epstein hanged himself in 2019, the inspector general said in a report released last month.
Last year, 13 female athletes who were sexually assaulted by Mr. Nassar each sought $10 million from the F.B.I., claiming agents mishandled the investigation, allowing him to continue abusing more victims.
The athletes in the lawsuit were abused by Mr. Nassar when they were at the Twistars gymnastics club, outside Lansing, Mich. John Geddert, who owned Twistars and referred injured athletes to Mr. Nassar, fueling a cycle of abuse, killed himself in 2021 after he was charged with human trafficking.
Some of the athletes, who were middle school or high school students at the time, were assaulted after the F.B.I. was first made aware of the abuse allegations in 2015, lawyers for the women said.
In 2021, the department’s inspector general sharply criticized the F.B.I.’s handling of the case, saying that Mr. Nassar had abused 70 or more young athletes from July 2015, when U.S.A. Gymnastics first reported allegations against him to the F.B.I.’s Indianapolis field office, to August 2016, when the Michigan State University Police Department received a separate complaint.