Concerns have been raised that an on-ceasefire republican paramilitary group could have access to 'home made' 3D printed weapons.
Two members of Óglaigh na hÉireann (ÓNH) are believed to have brandished the guns during a republican commemoration in west Belfast on Easter Sunday.
The well attended event at Milltown Cemetery to mark the anniversary of the 1916 Rising was organised by Republican Network for Unity.
During the commemoration a masked member of ÓNH, which called a halt to its armed campaign in 2018, read out a statement.
It has now emerged that up to four masked men were present, with two believed to be armed.
It has been speculated that the weapons may be have been manufactured using a 3D printer and computer software.
The technique effectively allows those with access to the right equipment to manufacture lethal weapons to a high standard anywhere.
It is not known if ÓNH, which emerged from a split with the Real IRA more than a decade ago, is involved in the production process or simply has access to a new supply route.
In the past weapons used by some hardline republican groups are believed to have been taken from Provisional IRA stocks
Supply routes for new weapons have also been difficult to establish.
Dr Dieter Reinisch, a researcher at the National University of Ireland in Galway, who closely follows dissident republican groups, previously said he believed the weapons on display at Easter were "newly acquired".
Dr Reinisch said while he did not know if the organisation had the "capacity" to produce their own weapons it is clear the organisation has access to new supply routes.
"No matter if they were shipped to Ireland or were produced in Ireland, it still shows they have new routes to acquire them," he said.
Dr Reinisch said he has been told by weapons experts the design on display on Easter Sunday was first produced in the US in 2020.
In its Easter statement ÓNH threatened to target loyalist leadership figures if nationalists or republicans are attacked as part of their ongoing anti-protocol campaign.
The statement also said the group has taken "lethal action" against former members and drug dealers.
Former SDLP Policing Board member and assembly candidate Dolores Kelly voiced concern at the development.
"The fact they have the ability to procure weapons is a matter for concern," she said.
"The people who have them have little regard for who the victims are, whether that be police officers, prison officers, journalists or innocent bystanders like Lyra McKee."
