WA prison lockdown after man found dead in cell

"Prison staff provided first aid and paramedics attended but the man was unable to be revived," a spokeswoman said.

"The circumstances surrounding the death will be subject to a police investigation.

"The prison is assisting the investigation and two units have been placed in lockdown to assist police.

"WA Police will provide a report to the state coroner."

The department would not confirm reports the man had been assaulted.

A WA Police spokesman said major crime detectives were attending the prison to establish the circumstances surrounding the death.

Three St John WA crews attended the facility, a spokeswoman said.