A prisoner has died at Casuarina Prison.
"Prison officers found the 32-year-old Aboriginal man unconscious in his cell around 1.30pm (on Sunday)," The Department of Justice said in a statement.
Officers and prison medical staff provided first aid before paramedics arrived but the man was declared deceased at the scene.
There were no suspicious circumstances surrounding the prisoner's death.
WA Police will prepare a report for the Coroner.