The murder of a young girl, whose bones were found dumped beside a highway in South Australia, is a mystery of a kind he's not seen before, says a senior South Australian detective.
The girl's remains were discovered along with a suitcase, clothing and other items near Wynarka, east of Adelaide, by a motorist in July.
Detective Inspector Greg Hutchins says in his 37 years in the force he has never seen anything like the "incredibly sad" case.
"There is so much wrong about this case - the little girl lost to the system, lost to society," he told reporters in Adelaide on Thursday.
"It's so wrong for a girl of this age to be murdered and dumped by the side of the road.
"It's so wrong that six weeks into the investigation we still don't know who this little girl is."
Insp Hutchins said it was frustrating to police that the identity of the girl remained unknown.
"We haven't been able to put a name to her and she can't have the burial that she rightly deserves," he said.
Detectives have now collected 256 names of young children who could be the little girl after consulting with a wide range of agencies.
Forensic specialists are working with the Australian Centre for Ancient DNA to establish a profile of the girl, who is believed to have been born between 2005 and 2006.
She is believed to have been aged between two-and-a-half and four when she died.
"If this girl has ever been recorded on any government database we will eventually find out," Det Insp Hutchins said.
"It's only a matter of time."
