A child's black dress and a quilt could hold the key to solving the murder of a young girl whose skeletal remains were found dumped beside a highway east of Adelaide.
Detectives on Tuesday began doorknocking homes and properties in a 25-kilometre radius around where the bones, a suitcase, clothes and other items were found last month as they continue to try to identify the girl and track down her killer.
Detective Superintendent Des Bray said the quilt found with the remains was considered very distinctive while the black dress is one of only 28 such dresses sold in South Australia about eight years ago.
"We know that dress was not released over the internet, wasn't released to other businesses and wasn't sold at markets and the like," Supt Bray said.
"Somebody in this area who saw a little girl wearing a dress like that ... they could very well solve this case."
The doorknocking involves Task Force Mallee detectives speaking with residents, businesses operators and staff, schools, doctors and anyone else connected with the local community.
Posters and letters will be distributed throughout the wider community as part of the operation.
A forward command post has been established at the Karoonda Football Club and anyone with information is asked to make contact.
Information provided by the community will be cross-checked with reports already provided to police and other leads that are being investigated.
More than 600 reports have been made to Crime Stoppers and 55 children have been eliminated as potential victims.
Police are also still trying to find a man, aged about 60, who was seen in the area carrying a suitcase on April 13 and again on May 26.
The murdered girl was aged between two-and-a-half and four, had fair hair and may have been killed as long ago as 2007.
Her remains were found alongside the Karoonda Highway near Wynarka.
THE SUITCASE MURDER - WHAT WE KNOW:
* Victim was a girl aged between two-and-a-half and four.
* She was likely Caucasian with fair hair about 18cm long.
* She was 90 to 95cm tall.
* She was killed at another location with her body put in a suitcase before being dumped.
* She was killed some time after early 2007.
