US government orders removal of Defcad 3D-gun designs
The US government has demanded designs for a 3D-printed gun be taken offline.
The order to remove the blueprints for the plastic gun comes after they were downloaded more than 100,000 times.
The US State Department wrote to the gun's designer, Defense Distributed, suggesting publishing them online may breach arms-control regulations.
Although the files have been removed from the company's Defcad site, it is not clear whether this will stop people accessing the blueprints.
They were being hosted by the Mega online service and may still reside on its servers.
Also, many links to copies of the blueprints have been uploaded to file-sharing site the Pirate Bay, making them widely available. The Pirate Bay has also publicised its links to the files via social news site Reddit suggesting many more people will get hold of the blueprints.
The Office of Defense Trade Controls Compliance wrote to Defense Distributed founder Cody Wilson demanding the designs be "removed from public access" until he could prove he had not broken laws governing shipping weapons overseas by putting the files online and letting people outside the US download them.Explosive force
"We have to comply," Mr Wilson told news magazine Forbes in an interview.
But he added the State Department's fears were ungrounded, as Defense Distributed had been set up specifically to meet requirements that exempted it from the arms-control regulations.
He welcomed the US government's intervention, saying it would highlight the issue of whether it was possible to stop the spread of 3D-printed weapons.
Unlike conventional weapons, the printed gun - called the Liberator by its creators - is made out of plastic on a printer. Many engineering firms and manufacturers use these machines to test prototypes before starting large-scale production.
While desktop 3D printers are becoming more popular, Defense Distributed used an industrial 3D printer that cost more than £5,000 to produce its gun. This was able to use high-density plastic that could withstand and channel the explosive force involved in firing a bullet.
Before making the Liberator, Mr Wilson got a licence to manufacture and sell the weapon from the US Bureau of Alcohol, Tobacco, Firearms and Explosives.
The Bureau told the BBC that any American could make a gun for their own use, even on a 3D printer, but selling it required a licence.
Mr Wilson, who describes himself as a crypto-anarchist, said the project to create a printed gun and make it widely available was all "about liberty".
Downloads for 3D-printed Liberator gun reach 100,000
The blueprint used to produce a 3D-printed plastic gun has been downloaded about 100,000 times since going online earlier this week, according to Forbes.
Defense Distributed told the news site it was surprised by the amount of interest its Liberator gun had generated.
Earlier in the week, the company demonstrated the firearm being fired
But even before any more guns come off the DIY printing presses, there are moves afoot to ban it.Metal detectors
Californian senator Leland Yee said he wanted a law passed to stop the manufacture of 3D-printed guns.
"I plan to introduce legislation that will ensure public safety and stop the manufacturing of guns that are invisible to metal detectors and that can be easily made without a background check," he said in a statement.
According to Defense Distributed, most of the 100,000 downloads have been in the US, followed by Spain, Brazil, Germany and the UK.
The blueprint has also been uploaded to file-sharing site the Pirate Bay, where it has become the most popular file in the site's 3D-printing category.Firing pin
It took Defense Distributed eight months to produce the firearm, which was assembled from separate components produced on an $8,000 (£5,000) 3D printer bought from auction site eBay.
While downloading the blueprints may not be illegal, any UK citizen who made and owned such a handgun could face arrest, according to the UK's Metropolitan Police.
"To actually manufacture any type of firearm in the UK, you have to be a registered firearms dealer (RFD)," it said in a statement.
"Therefore, unless you are an RFD, it would most definitely be an offence to make a gun using the blueprints. It may be legal for an RFD to manufacture a gun this way, as long as they had the necessary authorities."
One of the biggest headaches for law enforcers is the fact the gun is made from plastic - with only the firing pin made from metal.
New York congressmen Steve Israel and Chuck Schumer have sponsored legislation aimed at adding a 3D-printing provision to the US Undetectable Firearms Act, which requires all guns to be detectable.