A US man has been sentenced to more than four years in prison after pleading guilty to plotting to export a slew of pistols and machine guns to locations including Ireland and Scotland using an underground marketplace on the so-called Dark Web.

Kansas-based Michael Andrew Ryan, 36, who went by the name GunRunner while online, admitted using an illicit website called Black Market Reloaded to trade illegally in everything from Glocks to Uzis, the Department of Justice (DoJ) found.

The Dark Web, accessible using the Tor browser, is used by journalists and citizens in repressive regimes to access the web while living under censorship. Unfortunately, it is also used by criminals who use the technology – which hides online activity – to help sell drugs and weapons.

Ryan admitted to using the hidden services to send guns to locations including Cork, Edinburgh and Australia. The DoJ said many of the products' serial numbers had been "removed, altered or obliterated" and the stash included "hundreds of rounds of ammunition".

In his plea, he admitted to unlawfully exporting or attempting to export Beretta 9 mm pistols, 38 Special revolvers, 22 calibre Uzis, Highpoint .45 calibre pistols, Walther P22s, a number of different Glock models and bullets for each type of gun.

In addition to imposing the lengthy prison sentence of 52 months, US District Judge Daniel Crabtree also ordered Ryan to forfeit all firearms and ammunition seized by police during the investigation.

"With a computer and an internet connection, Ryan hosted an international arms trafficking business on the Dark Web, peddling firearms and ammunition throughout the world," said assistant attorney general Leslie Caldwell when the defendant first pleaded guilty in June 2016.

"Criminals of all stripes take advantage of technological advances to further their crimes and attempt to avoid identification and arrest.

"In this case [...] we were able to shut down dangerous criminal activity and secure the defendant's conviction – but we must remain vigilant to ensure that law enforcement retains the necessary capabilities to keep up with criminals."

Acting US attorney for the district of Kansas, Tom Beall added: "The fact international firearms trafficking has reached Kansas shows the power of the internet. This prosecution shows our law enforcement efforts are working."