Japanese police are reported to have confiscated five plastic gun-shaped items and 3D-printing equipment from the 27-year-old man's home in Kawasaki in April, with two of the five objects later found to be capable of firing real bullets.
The college employee has allegedly been charged in relation to these two objects, although no live bullets were found. Gun ownership is strictly regulated in Japan – the arrest marks the first application of this law to an item made using printing technology.
One of the guns appears similar in design to the prototype Liberator firearm developed by Texan law student Cody Wilson, who published the blueprints for his device online but was later forced to remove them by the US government.
"Police say this is the first time in Japan they have seized guns possibly made with the technology," reported Japanese broadcaster NHK World.
NHK said that police launched the investigation after the man posted videos of the guns online, and that the suspect has admitted using a 3D printer to make the devices although he did not think he was breaking the law.
The broadcaster reported that 3D blueprints for a handgun were found on the suspects computer and that police suspected he had sourced these online.
Tokyo-based news agency Jiji Press said the man was an employee of the Shonan Institute of Technology in Kawasaki and also owned a number of toy guns.
In October last year, British police claimed to have seized 3D-printed gun parts for the first time during a raid on a property in Manchester. They were later forced to clarify their statement after the 3D-printing community pointed out the similarity between the confiscated objects and harmless printer upgrade parts.
In November last year, American company Solid Concepts claimed to have built and successfully fired the world's first 3D printed gun.