The nine-month-old daughter who died at Surfers Paradise beach in NSW died, with the police now making arrangements to extradition the daughter of Queensland's daughter.
Queensland Police said they will continue to help their southern counterparts after establishing the death to the south of Coolangatta.
It was found that the baby's body lay in the sand at the waterfront at Beach Surfers Paradise. The tragic discovery was made midnight on Monday.
It is understood that after-mortem results show that the little girl was drowned and had been put into water at Tweed Tlyses, with a body eventually laying 30 kilometers north in Paradise Surfers.
The father of the baby and a 23-year-old mother is in custody but is not accused.
The NSW Police said detectives were about to travel to Southport on Wednesday and tried to extradition a 47-year-old man.
Upon returning to NSW, he will be charged with a warrant.
Meanwhile, child protection advocates ask for a query after two residents of the Gold Coast revealed that they had tried months ago to get help to the baby and their little brother.
The couple lived roughly with homeless parents before the baby died.
Child protection advocate, Hetty Johnston, says taxpayers deserve answers, and there must be a public inquiry into how the baby left in such a fierce situation.
"The public who needs to understand the system they are paying for and how to cut it," says the founder of Bravehearts at AAP.
"If they (children's services) knew about this family, we need to know what happened here. And if they did not know then something is really wrong there."
One resident of the Gold Coast told her to go to the police two months ago, fearing the children who were sleeping in the open air, near the beach.
"It was in the winter and the dunes were freezing every time the sun went down. I did not think that's fine for a baby or a little child," he said on Facebook.
"I noticed it immediately and it was monitored the following week. And if the authorities were doing the job correctly, this little girl would still be here!"
Queensland, Premier Annastacia Palaszczuk, Minister for Children's Security, Farmer's Day and Police Commissioner, Ian Stewart have refused to say if the family was on a child protection authority radar, indicating privacy concerns and continuing investigation.
Mr Stewart confirmed that there was a second child in question, saying that the baby's brother or sister was safe and looked after.
He suggested that there might be developments by the end of Wednesday as the police considered the consequences of post-mortem examination and daughter's toxicology tests.