Virtual blueprints for the world's first 3D printable handgun found a safe harbor Friday at file-sharing website The Pirate Bay, dodging a US government attempt to pull them off the Internet.

Defense Distributed, a Texas nonprofit that promotes the open-source development of firearms using 3D printers, withdrew the files needed to make the single-shot Liberator at the behest of the State Department on Thursday.

"This file has been removed from public access at the request of the US Department of Defense Trade Controls," said Defense Distributed on its website, which it embellished with the State Department seal.

"Until further notice, the United States government claims control of the information," it added without elaboration.

The State Department -- which confirmed it has been in contact with Defense Distributed, but gave no specifics -- is tasked with monitoring and licensing US arms exports through its Directorate of Defense Trade Controls.

"The United States is cognizant of the potentially adverse consequences of indiscriminate arms transfers, and therefore we strictly regulate exported defense items and technologies to protect our national interests," State Department spokesman Patrick Ventrell said.

But the crackdown on the Liberator clearly came too late to forestall the re-posting of its computer-aided design (CAD) files on The Pirate Bay, a popular peer-to-peer file sharing service that has been linked by its critics to film and music piracy.

"Nice try blocking this fed," wrote one Pirate Bay user, utilizing a slang word for federal government, in a comments section that veered strongly in favor of Americans' constitutional right to own and carry firearms.

Guns of all kinds have been a divisive issue in the United States since the December 2012 massacre of 20 children at Sandy Hook Elementary School in Newtown, Connecticut, that prompted fresh calls for tougher gun laws.

The white-and-blue .380-caliber Liberator bears a vague resemblance to its chunky namesake, the FP-45 Liberator pistol that the United States developed during World War II to be air-dropped to French Resistance fighters.

For the Liberator to conform with US firearms law, the CAD files call for an inch-big chunk of steel to be sealed with epoxy glue in front of the trigger guard, so that the weapon can be spotted by metal detectors.

The only other non-plastic part is a tiny nail that acts as the firing pin.

It was successfully test-fired last week with a .380-caliber bullet by its inventor, University of Texas law student Cody Wilson, although it exploded into pieces when a larger rifle bullet was used.

Wilson said Friday he sees a court battle looming on the horizon, in a case that raises questions about online freedoms and the possibilities of open-source 3D printing innovation in a borderless Internet world.

"I'm going to need some high powered legal help, but thankfully a lot of people have pledged support, including the Electronic Frontier Foundation," he told Motherboard, a technology blog (www.motherboard.vice.com).

"This is not the last time (legal action) is going to happen, so perhaps now it's time to have the fight," he added.

Supporters of tougher gun laws in the United States -- where there are nearly as many guns (an estimated 300 million) as there are people (about 315 million) and more than 30,000 gun-related deaths a year -- have voiced alarm.

"Stomach-churning," noted Senator Charles Schumer of New York, while Congressman Steve Israel said it shows the urgency of adopting his initiative to outlaw plastic homemade guns that might escape metal or X-ray detection.

No longer prohibitively expensive, 3D printers can be bought for about the same price as a top-end laptop computer. Brooklyn-based MakerBot, for instance, markets its desktop Replicator 2 for $2,199 with delivery in a week.

After the Newtown massacre, MakerBot took down CAD files for semi-automatic rifle parts that gun enthusiasts had posted in its Thingiverse CAD library, which otherwise features pen holders, lamp shades, a tabletop wind turbine and a printable microscope among its most popular open-source designs.