Two people, a man and a woman, are now in police custody over the death.
The pair are being questioned by police at a nearby watch-house.
Police have confirmed that the death is unrelated to schoolies celebrations taking place less than 1km away from the crime scene.
After the baby was discovered, police and paramedics raced to the scene and attempted CPR but sadly she could not be revived.
Seven reporter Bianca confirmed, "she was in the water at some point".
"All the emergency services who did attend here this morning have been distressed by what they saw and they have been offered counselling."
This article originally appeared on WHO.