Police are investigating the suspicious death of a four-month-old girl from Logan, south of Brisbane.
The baby girl was taken to the Logan Hospital on Monday morning with life-threatening injuries.
She was then transferred to the Queensland Children's Hospital in Brisbane in a critical condition, where she died on Tuesday afternoon.
A 35-year-old woman and 37-year-old man are assisting police with inquiries.
Detectives from the Logan Child Protection and Investigation Unit, and State Crime Command's Homicide and Child Trauma squads are investigating.
It is understood police are trying to determine whether the child's injuries occurred over a prolonged period, and at various locations.
The Department of Child Safety said it could not comment on individual cases.
Meanwhile, investigations are continuing into the death of a nine-month-old girl, who was found on a Gold Coast beach on Sunday night.
Local member Jim Chalmers said the community was "absolutely heartbroken" by the news.
"We will learn more about what has happened here," he said.
"But it really is a heartbreaking thing to have happened to a little girl so young and I know I speak for the whole community when I say that our hearts go out to everyone who loved that little girl."
