Homicide detectives are investigating the death of a four-month-old baby girl from the South West.
The infant was taken to Bunbury Hospital on Friday May 26 before being airlifted to Princess Margaret Hospital via the Royal Flying Doctor Service.
She died on Sunday May 28.
Major Crime Squad detectives are investigating the circumstances surrounding the girl's death and are waiting for the results of an autopsy.
An 18-year-old woman and a 21-year-old man from the South West are assisting police with their inquiries.
No charges have been laid.