Man denies owning 3D printer gun components
A man suspected of possessing a 3D printer with component parts to make a gun said the seized equipment had "nothing to do with a gun whatsoever".
It follows police raids in Greater Manchester on Thursday, in which officers seized computer equipment.
The arrested man said the suspicious parts were simply parts for the 3D printer.
Experts have also cast doubts on the claims, saying the parts were not sophisticated enough to make a gun.
3D printing technology works by building up layer upon layer of material - typically plastic - to create complex solid objects.
Greater Manchester Police said the components had been sent to the National Ballistics Service for further examination. The results are expected in the next few days.
The force said it "cannot categorically say" whether they had recovered the component parts that could make a "viable" gun.
US based printer maker, MakerBot Industries, which makes the components, said the company "believed" the items pictured were printer parts.
Jennifer Howard, the firm's director of PR, said: "We believe the two items pictured in the police seizure in Manchester are a piece for an extruder upgrade and a filament spool holder, both upgrade items you can print yourself.
"However, we cannot be 100 per cent sure, as we don't have a 360 degree view of the items or have not examined them ourselves."
Brian Derby, professor of material science at Manchester University, said the printer was a "hobbyist's machine".
He said: "It would make something that would look like a gun but it would not work as a gun."
"You would have to buy an expensive machine for about £50,000 but you could get a real gun.
"What is made is not likely to work. It is dangerous and likely to harm the person using it."Ballistics examination
The arrested man, who does not want to identified, was held following a police raid in Wythenshawe.
"I have no idea why they think it is part of a gun," he said.
"It's designed by the company that makes the printer to go in the printer to make it better."
Assistant Chief Constable Steve Heywood, who is a member of the national firearms group, said: "What I would say is that its actually incredibly difficult to create the whole weapon.
"And even if you do create the weapon its still incredibly difficult to fire it because it tends to blow up in your face."
The easy part of printing a 3D gun is getting hold of the plans and a printer to produce the parts.
Printers now cost only a few hundred pounds and are easy enough to use that anyone familiar with a computer should be able to get them churning out the bits. The plans have been widely shared online and a simple search should turn them up.
The hard part is making sure that you have a printer that can produce the parts to the right tolerances and uses a plastic strong enough to contain and direct the explosive shock unleashed when the firing pin hits the bullet.
Crudely printed 3D guns are much more likely to misfire and explode than propel a bullet towards a target. And then there is the problem of getting hold of bullets of the right calibre to fire from your printed gun. In the UK bullets cannot be bought without a firearms licence.
He said officers were "absolutely legitimate to get a warrant from the magistrate go in and do the search that we did".
A GMP spokesman earlier said if the tests showed the parts could make a functioning weapon it would be the "first ever seizure of this kind in the UK".
Asst Ch Con Heywood said: "We need to be absolutely clear that at that this stage, we cannot categorically say we have recovered the component parts for a 3D gun.
"What we have seized are items that need further forensic testing by national ballistics experts to establish whether they can be used in the construction of a genuine, viable firearm."
"It is prudent we establish exactly what these parts can be used for and whether they pose any threat."
The raid was part of GMP's Operation Challenger, which aims to "dismantle" organised criminal gangs.
Desktop 3D printers can be bought on the high street for less than £1,000, but prices can be as high as £10,000.
The world's first gun made with 3D printer technology was successfully fired in the US in May.
At the time, Europe's law enforcement agency Europol said it feared criminals would follow suit as the technology became cheaper and more user friendly.