The United States government has demanded designs for a 3D-printed plastic gun be taken off the internet.
Blueprints for the weapon have been downloaded more than 100,000 times from the Mega file-sharing site hosted by Kim Dotcom.
The US State Department wrote to the gun's designer, Defense Distributed, suggesting publishing the plans online may breach arms-control regulations.
Although the files have been removed from the company's site, the BBC reports it is not clear whether this will stop people accessing the blueprints.
They may still reside on Mega's servers.
Also, many links to copies of the blueprints have been uploaded to the file-sharing site the Pirate Bay, making them widely available.
