Provincial police are investigating the death of an inmate at Millhaven Institution in Bath, near Kingston, Ont.
Police say there was an incident involving inmates at the institution around 10 p.m. Sunday and one inmate suffered life-threatening injuries.
They say he was taken to a local hospital, where he died Tuesday.
OPP say the inmate has been identified as 28-year-old Darian Daignault.
They say an autopsy will be conducted to determine the cause of death.
Police say investigators are working with the office of the chief coroner, the Forensic Pathology Service and Correctional Service Canada.