Forensic pathologist and Victorian Institute of Forensic Medicine deputy director Prof David Ranson is heading to Britain to ask relatives of hanged English killer Frederick Bailey Deeming to come forward and give their DNA.
"A simple swab from the mouth of any person from the female line of the Deeming family will help us answer this fascinating piece of folklore," said Prof Ranson,
Deeming was a 19th century wife-killer, bigamist, thief and conman who murdered women and children on opposite sides of the world.
After his execution in Melbourne in 1892 for murder, it was speculated he committed the Whitechapel Murders. His brothers and sisters distanced themselves by taking the name Bailey, their mother's maiden name.
The skull of Kelly, who was hanged for murder at Old Melbourne Gaol in November 1880, was stolen from a glass cabinet there.
Last year, West Australian farmer Tom Baxter handed in a skull, saying it was the stolen one and refusing to explain how he came by it.
Prof Ranson, on behalf of the Victoria coroner, is trying to determine whether the skull is Kelly's or Deeming's.
Scientists at the Victorian Institute of Forensic Medicine had the skull examined by experts and gave it a CT scan, but were none the wiser, despite forensic pathologists managing to obtain DNA from one of Kelly's descendants.
Their problem is that not only is the skull a close match to the death mask of Kelly, but it also resembles one of Deeming. Both plaster casts are held at the jail, which is where both men were executed and buried close by each other in the prison yard.
They were later dug up and moved to Pentridge, and moved again when it was redeveloped.
When Deeming was hanged, more than 12,000 people in the street outside cheered wildly.
He had committed crimes on three continents, using at least 20 aliases.
Three months after his execution newspapers including the New York Times published stories that Deeming had been seen in Whitechapel in London's East End in 1888 buying knives.
In prison, he told fellow inmates that he was Jack the Ripper, but he never confessed to authorities.
Prof Ranson said: "We are hoping to find one of Fred Deeming's relatives in Ireland, England or Scotland who will be willing to help."