Minneapolis ex-police officer Derek Chauvin, convicted in the death of George Floyd, has been stabbed at an Arizona prison, US media reports say.
A source told AP the 47-year-old was seriously injured by another inmate.
The New York Times, citing two people with knowledge of the situation, also reported that he was attacked.
Chauvin is serving multiple sentences for the black man’s death, which triggered widespread protests against police brutality and racism.
The Bureau of Prisons confirmed in a statement that an inmate at the Federal Correctional Institution (FCI) in Tucson, Arizona was stabbed at 12.30 local time (19:30 GMT) on Friday.
The agency said employees contained the incident and “life-saving measures” were performed on the inmate, who was then taken to hospital. The name of the prisoner was not given.
Nobody else is thought to have been injured and Chauvin is reported to have survived the attack.
Brian Evans, a spokesman for the Minnesota attorney general’s office, said on Saturday that they had “heard that he (Chauvin) is expected to survive”.
The reported incident comes days after the Supreme Court rejected his appeal, in which it was argued that he had not received a fair trial for the killing of Mr Floyd – who died after Chauvin, who is white, knelt on his neck for more than nine minutes in 2020.
The killing – captured on a bystander’s phone camera – sparked global outrage and a wave of demonstrations against racial injustice and police use of force.