The riddle of a set of bones found in roadside scrub 40 years ago appears to have been solved after police used genealogical data from ancestry websites to track down the man's family.
Two schoolboys located skeletal remains in roadside scrub along the Playford Highway on Kangaroo Island in January 1983.
An anthropological examination revealed the bones belonged to a man of European ancestry, approximately 162 to 173 cm tall, who had died two to five years earlier.
But with no identification found on the deceased, decades passed without police coming any closer to cracking the case.
However, SA Police reopened the investigation in early 2021 and established a DNA profile of a bone sample, leading to a major breakthrough.
A genealogical investigation enabled the Australian Federal Police's genetic genealogist to create a family history profile using publicly available data from family history sites and traditional genealogical research methods.
Investigators narrowed down a family tree with 649 individuals to a single branch and after contacting the family discovered one of the older brothers, William "Billy" Henry Hardie, had disappeared from NSW in the late 1970s.
A comparison of a DNA sample from one of Mr Hardie's living brothers against the unidentified remains found "extremely strong scientific support" they are siblings.
The AFP also created a cranio-facial reconstruction image after conducting a 3D-scan of the skull but were unable to find a match with missing person databases.
Police are yet to make a formal identification but are working to establish what could have led Mr Hardie to Kangaroo Island and will prepare a report for the coroner.
Anyone who may have information into his movements has been urged to contact Crime Stoppers.
Police at the time determined the man's death was not suspicious.
