A United States judge has ruled to block the download of 3D gun blueprints online, arguing the weapons could be used by criminals and terrorists.

The ruling orders open-source digital firearms site Defense Distributed to temporarily block – rather than delete – 3D printable gun plans from its site.

However, hundreds of the designs had reportedly already been downloaded before the judge’s decision.

Judge Robert Lasnik issued the order on Tuesday, issuing the restraining order sought by eight attorneys general and the District of Columbia to block the sale of these prints.

According to the New York Times, Lasnik said that although there were “serious First Amendment issues” at play, there should be “no posting of instructions of how to produce 3D guns on the internet.”

“There are 3D printers in public colleges and public spaces and there is the likelihood of potential irreparable harm,” he said.

US President Donald Trump tweeted on the ruling, “I am looking into 3D Plastic Guns being sold to the public. Already spoke to NRA, doesn’t seem to make much sense!”

Founder of Defense Distributed Cody Wilson fired the first fully 3D printed gun in 2013 and shortly after posted the design.

Since then, he has been in an ongoing legal battle with the US government – being made to take down the designs in 2013 before successfully suing the government in 2015.

The dispute will return to court on 10 August.

An Australian issue?

The decision follows a case last month in Australia where Queensland Police seized three handguns from a man’s property, believed to have been created using a 3D printer.

The 27-year old man was charged with 12 offences, including possessing dangerous weapons and the manufacture of a weapon while not licensed.

Like in the United States, the issue of 3D printed weapons sits in a legal grey area in Australia with different states offering differing approaches.

For example, South Australia’s laws on ‘imitation firearms’ do not include mention of 3D printed guns, therefore making it unclear whether they are actually illegal under state law.

In New South Wales, the Firearms and Weapons Prohibition Legislation Amendment Bill 2015 specifically outlaws the possession not just of 3D printed weapons but also the “digital reproduction of a technical drawing of the design of an object” – making it illegal to even possess these files.

Queensland rejected a bill introduced by the Palmer United Party in 2014 that sought to make 3D printing of firearms illegal, with the government claiming it already had such protections in place.

However, when a man was arrested in Queensland for the possession 3D printing gun parts in 2015, he was not charged under any legislation that made printing firearms illegal.

At a national level, it is illegal under federal gun laws to manufacture a gun without a licence.