Researchers at Australia's first 'human body farm' have observed that dead bodies move significantly when they decompose and believe the movement could be important in death investigations.

Key points: An undergraduate researcher has found that movement occurs in bodies after death

An undergraduate researcher has found that movement occurs in bodies after death The findings could potentially impact future police investigations

The findings could potentially impact future police investigations Time-lapse photography of a corpse over 17 months revealed the surprising find

Researcher Alyson Wilson made the discovery using time-lapse cameras to film the decomposition of a donor body in 30-minute intervals over 17 months.

The observations are yet to be published in a peer-reviewed journal, but have intrigued Ms Wilson's colleagues.

The body farm is the Australian Facility for Taphonomic Experimental Research (AFTER), which was set up three years ago to investigate human decomposition under a variety of conditions to replicate crime scene scenarios.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 9 minutes 56 seconds 9 m An exclusive look inside Australia's human body farm ( Matt Wordsworth )

It lies in a secret bushland location on the outskirts of Sydney.

"What we found was that the arms were significantly moving, so that arms that started off down beside the body ended up out to the side of the body," Ms Wilson said.

"One arm went out and then came back in to nearly touching the side of the body again."

Ms Wilson, a medical science undergraduate at CQUniversity, said she expected some movement in the early stages of decomposition, but was surprised to see the movement continued for the 17 months of filming.

She said the movement could be a result of shrinking and contracting when the body's ligaments dried out, but the information could help with police investigations.

Alyson Wilson was in Mexico in January to help classify Mayan-era skeletal remains.. ( Supplied: Alyson Wilson )

"This research is very important to help law enforcement to solve crime and it also assists in disaster investigations," Ms Wilson said.

"It's important for victims and victims' families, and in a lot of cases it gives the victim a voice to tell their last story."

Building on research

The findings follow Ms Wilson's previous work, published last month in the journal Forensic Science International: Synergy.

In that study, Ms Wilson used the time-lapse camera to test whether a scientific equation to estimate the decomposition of a body in the northern hemisphere was applicable to the Australian environment.

"Until we had AFTER, most of the science on how bodies decomposed was based on the northern hemisphere, where the climate is different, the weather is different and even the insects can be different," she said.

This is the first time a time-lapse camera had been used to capture human decomposition, and it confirmed the equation could be used in the Australian environment.

'Astounding' movement of dead arms

It was because Ms Wilson had filmed the decomposition of the donor's body that she discovered that the limbs continued to move.

Ms Wilson filmed the decomposition of a donor body over 17 months using a time-lapse camera at AFTER. ( Supplied: UTS Sydney )

Her findings have excited forensic anthropologist and criminologist, Dr Xanthe Mallett, a senior lecturer at the University of Newcastle, who also conducts research at AFTER.

Dr Mallet, who supervised the study, said the findings were significant because investigators worked on the assumption that the position a body was found in was the position it died in — unless there was evidence the body had been moved by other people or by animals.

"What isn't known is that the body moves as part of the decomposition process and it's the first time that it's been captured, as far as I know," Dr Mallet said.

"I think people will be surprised at just how much movement there was, because I was amazed when I saw it, especially how much the arms were moving. It was astounding."

Establishing time since death

Dr Maiken Ueland, deputy director of AFTER, said there was some movement caused by insect activity and gas build-up in the body in the early to mid-stages of decomposition.

Dr Xanthe Mallet worked on the case of Karlie Pearce-Stephenson and her daughter Khandalyce. ( ABC Capricornia: Inga Stünzner )

She had not seen the extent of the movement in this study, but agreed the findings could impact on crime investigations.

"Being able to watch the human decomposition process in detail, as it happens, over time in 30-minute intervals will be invaluable in the search for better ways to establish time since death by determining when certain visible markers occur," Dr Ueland said.

"Knowing that body movement can result from the decomposition process rather than scavengers or original placement will be important when it comes to determining what happened, particularly if this movement is much greater than first believed."

Dr Ueland said a few donor bodies had been filmed using time-lapse cameras at the facility, but images were taken every hour and were viewed from outside an anti-scavenging cage, which slightly obstructed the view.

Mummied in Sydney

Ms Wilson's finding are just one of several to have come out of the facility.

Last year, a study was published that found human remains tended to mummify rather than decompose in the Sydney environment.

Dr Mallett says more facilities are needed to replicate different environments in Australia. ( Supplied: UTS Sydney )

No matter when the body had been placed in the facility — summer or winter — it continued to mummify even up to three years later.

It was not something Dr Mallett had seen before, and was a significant finding.

"Previously, if the police had asked me if a set of human remains were found and they were mummified, I would have said that it's likely that that person was left outside in autumn or winter," she said.

"It opens up the entire year for mummification in the correct circumstances, and it stops us from going down the wrong path [in investigations]."

One-of-a-kind in southern hemisphere

AFTER, which is owned and led by Sydney's University of Technology and works in collaboration with academics, police, and forensics, was the first taphonomic facility outside the US and is the only one in Australia and the southern hemisphere.

Taphonomy is the study of how organisms break down after death.

AFTER director Associate Professor Jodie Ward said their research ranged from replicating outdoor crime scene scenarios typical of missing person and homicide cases, to delivering national capacity-building programs for practitioners involved in mass disaster and humanitarian forensic operations.

"We are currently considering how the facility may be used to study different death investigation scenarios such as indoor environments, drowning, fire, or concealments, to further aid criminal and coronial investigations," Dr Ward said.

Thanks to body donors who are helping science

They currently have 70 donor bodies.

"This research and training is only possible because of the generous and invaluable contribution our donors and their families have chosen to make to forensic science," Dr Ward said.

There were moves to get a centre operating in central Queensland, which has not progressed, but according to Dr Mallett, there are plans for another location.

She said that could happen within two years, although it takes a lot of time to establish the facilities.

While the Sydney facility is in a bush environment that replicates many areas in Australia, there are many other environments in the country.

"It's essential that we replicate as many of those as possible, because in other environments in Australia — imagine the desert — the remains would skeletonise quickly depending on the time of year they are put out," Dr Mallett said.

"We need as many facilities, in different locations, in different altitudes, so we can get as much information in an Australian context as possible."