Despite Australia having some of the toughest guns laws in the world, people are still managing to get their hands on illegal weapons through a variety of avenues — including in the mail.

The Australian Medical Association (AMA) have recently called for a national gun register to help reduce gun violence.

But the problem with any gun registry is that it does not track weapons illegally assembled in Australia.

Police say criminals are developing more sophisticated ways of obtaining or creating weapons, with new technology such as 3D printers growing in popularity.

Chief inspector Wayne Hoffman, a ballistics expert, said the NSW Police Force was interested in 3D-printed handguns as part of their ongoing ballistics research.

"A lot of people call this an emerging trend, and we have to go with that — 3D printers are a very important bit of technology, so we want to keep on top of it," he said.

He said police had been able to use a 3D printer to create a revolver out of plastic filament capable of discharging small arms ammunition.

"The tests that we have done show that it can discharge a bullet, which will enter a human body at a depth of 14 centimetres, which could inflict a lethal wound upon a human being," he said.

Chief inspector Hoffman said while police had not come across any 3D-printed handguns in NSW, some had been seized in Queensland.

3D-printed weapons used for research by the NSW Police Force. ( ABC News: Connie Agius )

International mail 'a popular method for firearm delivery'

Organised crime groups have also relied on other unconventional methods to import illegal firearms.

The Australian Criminal Intelligence Commission's (ACIC) latest report on the issue noted that criminals were increasingly using international mail to import illegal gun parts and accessories.

The fast delivery, accurate tracking and limited scrutiny due to the high volume of mail entering Australia, make it an attractive method.

Chief inspector Hoffman said a recent incident was Strike Force Maxworthy, when the NSW Police dismantled a criminal syndicate responsible for importing illegal handguns from Europe to Sydney.

"A NSW police investigator seized a firearm off the streets of Western Sydney," he said.

"We traced that firearm and found out that it was only 11 or 12 weeks before that it had been manufactured from the factory in Austria and that commenced the investigation."

The weapon was a Glock pistol and the subsequent investigation resulted in the arrest of three men, including a post office licensee, who pleaded guilty to importing the parts to Australia using fake consignment data.

"They were disassembled by the criminals and they mailed the barrels and the top slides and the frames in different packages," he said.

"And then once received here in Australia they were put together, assembled very easily, and then used in crime."

Firearm parts and accessories that Australian Border Force investigators allege were illegally imported through the mail in Victoria ( Supplied: Australian Border Force )

Rise in homemade weapons 'a threat to the community'

Chief inspector Hoffman said all homemade manufacturing of weapons was dangerous and a threat to the community.

He said there was one particular "do-it-yourself" method that they were increasingly concerned about.

Chief Inspector Wayne Hoffman with 3D-printed guns. ( ABC News: Connie Agius )

"At this current moment, more of the threat is the homemade firearms — that is replica pistols that have been made to fire modified and other items which are assembled in the form of a gun to discharge a bullet," he said.

"We're getting more of that into the laboratory at the moment and not 3D firearms or parts.

"People making homemade firearms, putting together parts and using printers are putting themselves in danger — there is no inspection, no quality or testing."

Chris Dawson, CEO of the ACIC, said they were keeping an eye on the emerging trend of homemade weapons across Australia, along with other firearm trends.

"We've traced 1,000 handguns that are conventionally produced by gunsmiths and manufactured by people with metal working skills in which they can put parts together," he said.

"It's not easy or by any means at the standard of a professional firearm manufacturer."