The headless remains of infamous Australian outlaw Ned Kelly has been identified, officials said on Thursday, putting an end to decades-long mystery surrounding the whereabouts of the body.

Kelly led a gang of bank robbers in Australia's southern Victoria state in the 19th century. He was hanged in 1880 for murder at Old Melbourne Gaol in November of the same year after killing three policemen. Kelly's final resting place was unknown, but it was long suspected that his body lay alongside 33 other executed inmates in a mass grave at a prison. His body went missing after it was thrown into the mass grave. 

The recent discovery of Kelly's body has solved a mystery that dates back more than 130 years.

Reports are that officials pinpointed the location of the grave site in 2008 and later exhumed the bodies for analysis.

It was a DNA sample from one of Kelly's descendants that confirmed that one of the skeletons, which was missing most of its skull, was indeed that of the notorious killer, said Victoria Attorney General Robert Clark. 

Doctors and scientists at the Victorian Institute of Forensic Medicine managed to identify Kelly's body after taking a DNA sample from Melbourne teacher Leigh Olver, Kelly's sister Ellen's great-grandson, according to the Agence France-Presse.

To think a group of scientists could identify the body of a man who was executed more than 130 years ago, moved and buried in a haphazard fashion among 33 other prisoners, most of whom are not identified, is amazing, Clark said in a statement.

Kelly is considered a cold-blooded murderer by some, and was also seen as a folk hero and symbol of Irish-Australian defiance against authorities from Britain.

The wear and tear of the skeleton is a little bit more than would be expected for a 25-year-old today, said institute director Professor Stephen Cordner, told the AFP. But such was Ned's life, this is hardly surprising.

The whereabouts of Kelly's skull remain a mystery, Cordner said. 

Authorities believed Kelly was born in 1854 or 1855. He became an outlaw two years before he was hanged. During that time Kelly took on corrupt police and greedy land barons. He managed to survive a shootout with police in 1878, but an 8,000-pound bounty was offered for Kelly's brother Dan and friends Joe Byrne and Steve Hart. It was the largest reward ever offered in the British Empire for anyone who found them — dead or alive.

A final gunbattle at Glenrowan led to the death of three of the gang members and Kelly, who was dressed in home-made plate metal armour and helmet, was wounded and arrested.

Local reports stated that the bullet wounds Kelly suffered to his elbow, thigh and foot can still be seen in the skeletal remains.

Olver has said he was relieved to finally have some closure.

It's such a great relief to finally have this side of the story resolved, he told reporters, adding that he hoped a suitable resting place could be found for his relative. A place of dignity, a place very appropriate. Where that is will be determined later.

Kelly has been memorialized in films where Rolling Stone Mick Jagger played the lead role in the 1970 movie Ned Kelly. Heath Ledger also starred as the bandit in a 2003 remake that featured Orlando Bloom and Geoffrey Rush.

Kelly also inspired books such as Peter Carey's novel True History of the Kelly Gang, which won the 2001 Booker Prize.