Four-Month-Old Baby Girl Found Dead In Logan

A day after a baby girl was found dead on a Queensland beach, a four-month-old girl has died in suspicious circumstances.

Police say a woman, 35, and a man, 37, are assisting with their inquiries into the death on Tuesday of the four-month-old infant from the Logan District.

She was taken to Queensland Children's Hospital on Monday morning with life-threatening injuries before dying there on Tuesday.

Detectives are also investigating the death of nine-month-old baby girl whose body was found on a Gold Coast beach on Monday.

A passer-by found her body on Surfers Paradise Beach, lying in the sand at the edge of the water in the middle of the night.

READ MORE: Homeless Parents Arrested Over Death Of Nine-Month-Old Girl Found On Beach

Two Gold Coast residents have revealed they tried months ago to get help for the nine-month-old girl, who was living rough with her homeless parents before she died.

The baby's 48-year-old father and 23-year-old mother are in custody but have not been charged.