Sydney - Australian police said Wednesday a young child's skeleton found in a suitcase earlier this year was the daughter of a woman whose bones were found 1 100 kilometres away five years ago.
Police said the discovery was a breakthrough in the cases that have baffled investigators, and that the mother and child had suffered "violent, deliberate deaths".
"This is one of the most shocking crimes -- shocking and unimaginable -- and another family has been torn apart and devastated," detective superintendent Des Bray told reporters in Adelaide.
"Those people that are responsible for this crime are truly evil and must be quickly caught and held to account for what they've done."
The woman, dubbed Angel by police as she was found with a T-shift with the words "Angelic", was named as single mother Karlie Jade Pearce-Stevenson, born in 1988.
Her bones were discovered in 2010 in Belanglo State Forest in New South Wales state -- notorious as the site where seven backpackers' bodies were dumped during a killer's murder spree in the 1990s.
The remains of the child -- Khandalyce Kiara Pearce, born in 2006 -- were discovered in July by a passerby near a highway close to Wynarka, a small town outside Adelaide in South Australia state.
Both were from Alice Springs -- a remote town in central Australia some 1,700 kilometres north of Wynarka and 2,600 kilometres northwest of Belanglo. They were last seen on a highway in South Australia in 2008.
Also Read: Former Australian PM accused of being a paedophile
There is no link with the other Belanglo killings, and police said it was "premature" to talk about suspects, but that Khandalyce's father and Pearce-Stevenson's family were not under suspicion.
Pearce-Stevenson's mother, who has since died, initially reported her daughter as missing in 2009.
But she withdrew the report six days later saying she was "safe and well, but did not want family contact at that time", detective superintendent Mick Willing told reporters in Sydney.
While the mother and daughter were finally identified through DNA, investigators said the breakthrough came through two calls to a police hotline.
One caller mentioned the missing person's report, while another supplied a photograph of a girl they thought could be linked to the bones in the suitcase, which then helped investigators track down government and medical records.
"You could say that initially we were looking for a needle in the haystack but we didn't know what the haystack was," Bray said as he described the investigation spanning the vast continent, two states and a territory as "challenging".
"We've now actually got the haystack and we think we're working towards a successful conclusion but there's a lot of work to be done."