To have the remains of a little girl but after more than two months still have no idea who she is.

"This is the complete opposite to the William Tyrrell situation where they've got the identity and the devastated family but no body," South Australia police Detective Inspector Greg Hutchins says.

"We are in reverse. We've got the kid and no devastated family."

On a rural road in South Australia, a motorist pulled over to answer nature's call and spotted a tattered black suitcase.

Its contents were scattered on the orange dirt and scrub – aged, dirtied children's clothing and the skeletal remains of a young girl.

That was on July 14, 2015.

Eleven weeks down the track no one has come forward to put a name to the fair-haired little girl – aged between two-and-a-half and four – who police have no doubt died a violent death.

Links to high profile cases like William Tyrrell and missing British  toddler Madeleine McCann were ruled out early on.

A list of 256 children's names compiled from Commonwealth databases and provided to police in August have all but been ruled out.

Investigators are reluctant to detail how the list was collated but it is understood records, including immunisation and Centrelink, were searched.

If a child got to a certain age and stopped appearing on records, her name might have made the list.

Homicide squads in states and territories around Australia were given names and a description of the little girl.  They were asked to check with schools whether there were any missing students matching that description.

Police were hopeful the list would provide a breakthrough but with a majority of names now eliminated, they are back to square one.

Detectives have gone back to the Commonwealth agencies and asked them to widen the search criteria.

They now have a list of thousands of children's names to sift through.

These names will be cross-referenced against state records and some will be eliminated from the investigation quickly. Door knocking will be the last resort, police don't want to cause unnecessary panic.

"Unless this child was in a total vacuum and never registered, she has to be in a data base somewhere on a federal and state level," Inspector Hutchins, from the major crime investigation branch, said.

"But we can't rule out she was living in a very dysfunctional environment and had never been registered."

The case has similarities to the discovery of a girl's skeleton in NSW's Belanglo  State Forest in 2010.

Her bones also showed signs of injury and it's believed the girl, known as Angel, could have been there as far back as 2000. Police have been down many avenues to identify this girl, including those never explored by NSW homicide investigators before.

Inquiries were made with state agencies that deal with young runaways and the DNA of relatives who feared the bones may have belonged to their missing loved one was matched – unsuccessfully – against Angel's.

They looked at the cases of missing children, like Quanne Diec, a 12-year-old who disappeared from Granville in 1998, but none matched up. Angel's DNA profile was handed to interpol but to date, investigators haven't had any matches.

They also explored the theory the girl came into Australia illegally and wasn't registered on any immigration records.

In a first for the NSW homicide squad, a facial anthropologist was brought in to create a image of what the girl's face may have looked like. A stable isotopes analysis was also done on her bones.

"The chemical markers that were in her tissue and bones indicated she had not spent much time in Australia," Detective Sergeant Tim Attwood told Fairfax Media.

Serial killer Ivan Milat murdered several backpackers in the same forest Angel was found in. While he was in jail when police believe Angel was killed, his nephew Matthew, who murdered his mate in the same forest in 2010, was questioned over any potential links to the Angel case. But detectives concede he is not a strong line of inquiry.

Like the Wynarka case, police made extensive inquiries about the clothing Angel wore, particularly a shirt with the word "Angelic" across it. A description of the T-shirt made in China was widely published but not one person has contacted police to report owning one.

The inquiries have been exhaustive and relentless but today her remains lay in a box in the Glebe Morgue unidentified.

It is a long, painstaking process that South Australia's Task Force Mallee is now facing.

SA-based detectives believe the girl found in Wynarka was killed between 2007 and 2009 before she was put in the suitcase and dumped on the side of Karoonda Highway.

Disturbingly, police believe the suitcase was moved from another location and its contents possibly rifled through before the person who reported it to police came across it.

Police say if the girl's remains were decomposed, they wouldn't have weighed much and could have tumbled out of the suitcase with the clothes undetected.

Images of her clothing have been circulated far and wide, missing persons records haven't yielded any results and there is a process underway to extract a DNA profile from her bones that will allow for familial searches. Yet none of this has been enough to convince a relative or friend to come forward.

"Somebody would have loved this little girl, someone gave birth to this little girl, someone bought her lovely clothes,"  Inspector Hutchins said. "Somebody loved her and we ask that person to be the voice for this girl."

Inspector Hutchins said immunity from prosecution could be on the table for those not directly involved in murder of the Wynarka child.

"If you're on the periphery of this crime, come to us before we come to you," he said. "There is things we can offer, like immunity."

Until someone's conscience prompts them to come forward, both the girl in the suitcase and the girl in Belanglo State Forest will remain nameless.