An Aboriginal man died at Greenough Regional Prison, in Narngulu, Western Australia on Tuesday afternoon.
The 45-year-old man collapsed while playing basketball at around 4.35pm, according to preliminary reports.
The Department of Justice advised that prison officers and medical staff provided first aid to the man before an ambulance arrived, but paramedics declared him deceased at the prison.
WA Police will file a report to the Coroner and a Coronial inquest will be held, as is done for every death in custody.
More than 20 Indigenous people have died in custody nationwide in 2022.
According to the Australian Institute of Criminology's National Deaths in Custody Program, almost 530 Indigenous people have died in custody since the end of the Royal Commission into Aboriginal Deaths in Custody concluded in 1991.