Former US national gymnastics team doctor Larry Nassar has been stabbed several times at a Florida prison.
Nassar, who is serving up to 175 years for molesting gymnasts, received multiple injuries during a fight with another inmate on Sunday, CBS News reported.
He is reportedly in hospital in stable condition and is said to have suffered a collapsed lung.
The 59-year-old was jailed for sexually assaulting athletes he worked with, and possession of child abuse material.
During the assault, Nassar was stabbed twice in the neck, twice in the back and six times in the chest, a prison union leader told NBC News.
The Federal Bureau of Prisons confirmed an inmate was assaulted at 2.35pm (US time) at United States Penitentiary Coleman in Florida, where the disgraced former doctor is serving time.
"Responding staff immediately initiated life-saving measures", the agency said. The inmate was taken to a local hospital "for further treatment and evaluation".
An internal investigation has been launched, and no staff or other inmates were injured in the incident, the statement said.
Nassar admitted to sexually assaulting athletes while he worked with the USA Gymnastics programme and Michigan State University, where he maintained a clinic.
More than 330 women and girls at USA Gymnastics and Michigan State University have accused Nassar of sexual abuse.
Olympic gold medallists Simone Biles, Aly Raisman and McKayla Maroney have all testified about surviving Nassar's abuse.
Some of the young athletes said they had come forward about the abuse to adults, including coaches and doctors, but were dismissed.
An investigation into the FBI's handling of the scandal, published in 2021, found the agency made a series of mis-steps, including delays and cover-ups, which allowed Nassar's abuse to continue for several more months after the case was first opened.
The agency's own watchdog found the FBI disregarded allegations about Nassar and made early errors in its investigation.
Several women who were sexually assaulted by Nassar - including Raisman, Biles and Maroney - have sued the FBI for $US1 billion ($NZ1.6b) for mishandling credible complaints of sexual assault.
USA Gymnastics has agreed to pay $380m to Nassar's victims, while Michigan State reached a $500m settlement with survivors.
- BBC
This story was first published by the BBC.