It is believed the guns seized at Dublin Port on Friday were destined for republican paramilitaries in the Border area around Newry. The type of weapons involved, Luger pistols, and the method of the smuggling operation suggest it was not the work of the IRA. The IRA is also unlikely to have any shortage of such weapons, and pistols are rarely used in IRA attacks.
The importation of weapons at such a sensitive point, when the organisation's political wing, Sinn Fein, is embarking on a talks process in the North would also tend to suggest it was not their work. Garda sources indicate, however, that the IRA has not been ruled out of their investigations.
The Garda Special Branch is maintaining surveillance on IRA figures in the Republic. As a result of such surveillance gardai prevented a massive armed robbery by the IRA at the AIB bank centre in Ballsbridge, Dublin, last week.
It is believed the Dublin IRA figures were planning the robbery, which could have netted them as much as £8 million in used notes, for as long as a year.
It is believed they had decided to go ahead with the robbery despite the ceasefire because the organisation has run out of money. There is a possibility that if the IRA was to embark on a series of armed robberies to sustain itself during a ceasefire it would need weapons like the pistols found in Dublin Port.
Other possible destinations for the weapons include the Irish National Liberation Army (INLA), the splinter republican group which has not declared a ceasefire. It has imported similar caches of weapons before, the last being in 1995 when 26 guns were intercepted by gardai in a van travelling north out of Dublin.
That operation also originated in the Netherlands, the source of the container in which the guns were found at the weekend.
Sources close to the INLA in Belfast said the guns did not belong to the organisation. Two other republican groups are also under consideration. The Continuity Army Council (CAC) group, which gardai link to Republican Sinn Fein, is against any ceasefire. Little is known about its current size or membership but it is probably a very small group. Less is known about its armoury and its method of arms importation.
The Official IRA is the fourth possible group under consideration. It is known to have a group in Newry which was recently at loggerheads with Provisional republicans in the town. In an outbreak of hostilities in the middle of this month four men, two from either side, suffered gunshot wounds to the legs. Sources close to the Official republicans said at the weekend the guns were not theirs.
Gardai believe two Newry couriers arrested when they arrived to collect the container were unaware of the contents. They were to deliver the container to a depot in Newry. Both were released after being held for a day.
It appears the discovery of the gun shipment came as a surprise to gardai. It is understood the container had been under surveillance for several days by customs officers, who suspected it might contain drugs.
It is less likely, but possible, that the weapons were being smuggled into Northern Ireland by criminals involved in drug dealing. There are a number of active drug-smuggling groups in the North, some including ex-loyalist and republican paramilitaries.
These groups could be facing attacks from the IRA, which killed eight drug dealers in the North during its first ceasefire. It could be that they are arming themselves in preparation for attacks by the IRA, which used the cover name, Direct Action Against Drugs (DAAD), when claiming the murders of the drug dealers.
Drug gangs, mainly based in Belfast and Ballymena, Co Antrim, are known to have links with suppliers and organised criminals in the Netherlands.
Another possibility, according to security sources on both sides of the Border, is that republican paramilitaries who are retiring from terrorism may be moving into full-time criminality. There were indications only last week that this may already be happening. Two vans were hijacked by masked and armed men in separate incidents on Wednesday.
In one incident, a gang of men hijacked a lorry containing detergent for Dunnes Stores at Ballygawley, Co Tyrone. The driver was taken captive and driven to Dublin, where he was released unhurt at a bus-stop on the northside. The RUC are understood to believe the hijackers mistook the lorry for one carrying alcoholic drink.
In the other incident a van was hijacked in north Belfast.