A man has died after being found unconscious in his cell at Perth's Hakea Prison, with the circumstances described as non-suspicious.
Prison officers and paramedics attempted to resuscitate the 50-year-old prisoner after he was discovered on Monday afternoon.
"Preliminary reports indicate there were no suspicious circumstances," Western Australia's Department of Justice said in a statement on Tuesday.
"In accordance with all deaths in custody, WA Police have investigated and will prepare a report for a coronial inquiry."
Hakea, in Perth's southeastern suburbs, is WA's main facility for male prisoners who are on remand or have just been sentenced.