Two British men have been jailed for a total of 14 years after they sold "party packs" on the dark web market Silk Road.

Ryan Michael Milligan and Ryan Thomas McManus, both from Northern Ireland, used the service to peddle illegal drugs including cocaine, MDMA, herbal cannabis and mephedrone, both within the UK and as far afield as the US and Russia.

The pair were arrested by police in August 2013 and convicted alongside Conor Devenney, who worked as a courier for the scheme and died before sentencing could take place.

Officers who searched their properties seized phones, computers, iPads, passports, banking details, printers and packaging, as well as large amounts of drugs, among them LSD substitute tablets decorated with the face of the cartoon character SpongeBob SquarePants.

David McFarland, a judge, told Belfast Crown Court: "This was a very detailed investigation on a major drug operation which had the potential to inflict major damage on the wider community."

According to the National Crime Agency, Milligan and McManus would order the drugs through emails, online forums and instant messaging from suppliers in the Netherlands, China and North America.

They paid for the drugs using money transferring services and digital currencies such as Bitcoin, which they also accepted as a means of payment.

The substances were then sent through legitimate couriers to virtual addresses or the addresses of associates.

John Costley, operations manager at the NCA, said: "Drugs destroy communities and anyone who thinks buying and selling them in the virtual world is safer than buying and selling them on the street is very mistaken.

"The National Crime Agency together with its partners, locally, nationally and internationally, will protect the UK public by pursuing those involved in serious organised crime and will put them before the courts."

All three men pleaded guilty at Belfast Crown Court earlier this year. A financial investigation is ongoing.