Spanish police have dismantled an illegal workshop that was using 3D printers to produce guns for a suspected far-right group.
Pictures released on Sunday showed officers in Tenerife in the Canary Islands carrying out the joint operation with the Treasury Office.
The operation took place on September 14 last year but remained secret by order of a judge until police were cleared to release the details on Sunday.
The facility housed working 3D-printing equipment that could manufacture gun barrels in just two minutes, Spain's National Police said in a statement.
There were also manuals on terrorism, urban guerilla warfare and how to make explosives at home using a 3D printer, as well as white supremacist literature and a pistol holster bearing the insignia of the German army during the Second World War.
A specialist team of dogs from the police's TEDAX bomb squad sniffed out chemical substances that could be used to make explosives, the statement said.
One man was arrested during the raid. A police report said the 3D printing of weapons is part of a new, emerging threat in illegal arms trafficking in Europe.
It cited a terrorist attack in Germany in October 2019, where a Jewish synagogue was attacked with a rifle made with a 3D printer.