A 52-year-old Aboriginal man died at Albany Health Campus in the early hours of Wednesday morning, having been transferred from Albany Regional Prison to the hospital.
The WA Department of Justice said on Thursday that the man, who was terminally ill, was taken to the hospital after suffering a medical episode on Sunday, 20 July.
WA Police will prepare a report for the State Coroner, as is mandatory for all deaths in custody.
More than 600 Indigenous people have died in custody in Australia since the Royal Commission into Aboriginal Deaths in Custody brought down its findings in 1991.
