Where in the world is Nedâ€™s head?

The Baxter Skull was later found not to belong to the infamous bushranger at all. Picture: Courtesy CSRIO Source: Supplied

Ned Kelly's famous iron mask. Source: News Corp Australia

IT remains one of Australia's biggest mysteries and has inspired countless theories, books and even a few conspiracy theories.

But what really happened to Ned Kelly's skull remains largely unknown in a story that has captivated Australia for more than 136 years.

Now for the first time since his death a comprehensive study of scientific evidence has revealed the secrets of Ned Kelly, uncovering the truth behind his burial, post-mortem and what became of his missing skull.

Australia's most notorious bushranger was hanged on 11 November 1880 at the Melbourne Gaol.

He was buried at a mass grave in Pentridge Prison and in August 2011, anthropologists confirmed skeletal remains, minus a skull, belonged to Kelly.

A CAT scan of the Baxter Skull, once believed to belong to Ned Kelly. Picture: Courtesy CSRIO Source: Supplied

The bushranger's notoriety has made him a legend to many Australians due to his loyalty to his family, but he remains a violent offender to others.

But the mystery of what happened to his skull has been almost as captivating as the man himself.

Now a comprehensive book from CSIRO Publishing,Ned Kelly: Under the Microscope, aims to provide definitive answers to the mysteries of Ned Kelly's life and death, using scientific analysis.

Editor of Ned Kelly: Under the Microscope, Craig Cormick has gathered contributions from more than 30 experts to address many of the myths that have arisen around the Australian folk hero.

The skeletal remains of Ned Kelly show injuries he received. Picture: Courtesy CSRIO Source: Supplied

Looking at anthropology, DNA studies, metallurgical analysis of the gang's armour, and archaeological digs at Pentridge Prison and Glenrowan, the book addresses a wide range of scientific research relating to Ned Kelly and his gang, and what it has revealed.

Speaking to news.com.au, Dr Cormick said he aimed to combine two great passions, science and Australian history, to help solve the mystery of where Kelly's head could be.

"Lots of books have been published about this, but this one is based on the clarity of science," he said.

Ned Kelly's death mask (left) and a skull at the Old Melbourne Gaol in the 1970s. The skull belonging to Kelly, the infamous Australian bushranger, was stolen. Source: AFP

A skull, believed to be Kelly's, was displayed at the Old Melbourne Gaol until it was stolen in 1978 but DNA testing later proved that the skull was not his at all.

Western Australian farmer Tom Baxter claimed he had the skull but testing later proved it did not match the Kelly death mask.

Dr Cormick said Kelly's skeleton was found with a piece of skull, believed to be removed after hanging to ensure the neck was broken.

He said Kelly's skull would be missing that peace of bone at the back.

West Kimberley farmer Tom Baxter and skull and shotgun rifle used to shoot Ned Kelly at the siege of Glenrowan. Source: News Limited

"So that question still remains where is Kelly's skull and who did this one belong to?" he said,

According to Dr Cormick, there are three popular theories as to what happened to the bushranger's head.

1. It was crushed during excavation of the old Melbourne Goal in 1929;

2. A senior member of the Catholic clergy buried it in secret;

3. It was stolen by craniologist Archibald Hamilton who died soon after Kelly, leaving his wife to dispose of his worldly possessions.

Ned Kelly is still a polarising figure today. Source: News Corp Australia

Dr Cormick said Ned Kelly remained a fascinating topic for many Australians and a lot of people saw themselves behind the infamous mask.

"His remains have revealed many answers to long-held debates about him, including where he was buried, whether a post-mortem was conducted on him, and what became of his skull," Mr Cormick said.

"The book explores the science undertaken by researchers at the Victorian Institute of Forensic Medicine, including identifying skeletal remains, analysing DNA samples from Ned Kelly's blood-soaked possessions and physically matching injuries on bones to known bullet wounds that Ned Kelly sustained."

Ned Kelly: Under the Microscope, edited by Craig Cormick, available now, in book shops and online $39.95.