A maxium-security Edmonton prison is under lockdown after the suspicious death of an inmate Saturday night.

Spokesperson Rick Dyhm said the inmate at the Edmonton Institution was found at about 9:30 p.m. MT.

"We had an incident on one of the units," Dyhm said. "An inmate was deceased on the scene and we're investigating."

He did not say whether the inmate was found in a cell or a common area.

Homicide detectives from the Edmonton Police Service have been brought in to investigate.

The victim's name was not released.

During a 24-hour lockdown, no one can visit, there is no recreation time, and inmates must eat their meals in their cells.

Dyhm said it's not clear how long this lockdown will last.