Police are investigating the death of a man at the city's maximum-security prison Thursday night.

Homicide detectives say Ryan Holteen, 32, died at 10:00 p.m. Police officers and paramedics were called to the Edmonton Institution, but the inmate was declared dead when they arrived.

The medical examiner did an autopsy Friday, but detectives say they will not release the cause of death at this time.

The Edmonton Police Service and Corrections Canada are working together on the investigation.