The Provisional IRA has been amassing its hidden arsenal for more than 30 years.

The security services estimated the arms caches held at least 588 AK-47s, 17 Duska heavy machine guns - capable of shooting down helicopters - and 11 rocket propelled grenade launchers (RPGs).

There was also 2,658kg of semtex explosive, and nine Surface-to-Air Missiles (SAMs), although these were never used and experts speculate that either the missiles were defective or no-one within the organisation knew how to use them.

Other items included flame-throwers, more than 100 hand grenades, machine guns, and Webley revolvers.

Weapons were mostly smuggled into the province from Libya and America, and were stored in underground bunkers. They were scattered across secret locations in the north and south of Ireland, although most were believed to be concentrated in the counties of Kerry, Cavan and Meath.

According to experts, even the IRA’s own leadership may not know the full extent of its holdings beyond the general assessment that this is one of Europe’s largest stocks of weapons.

"Nobody could be totally accurate. Maybe not even the IRA know all the weaponry its members have around the place," said Sean Boyne, a defence analyst with Jane's Information Group.

"There could be some stuff hidden and forgotten that might turn up later."

That uncertainty, and the refusal of inspectors to reveal details of the inventory of those weapons which have been destroyed, has been seized upon by loyalists who say that the deal is worthless without complete transparency.

"We do not know how many guns, the amounts of ammunition, explosives - nor were we told how the decommissioning was carried out," said the Rev Ian Paisley at a news conference in Belfast.

The military estimates were calculated using information obtained by Britain officials from Libyan leader Colonel Gaddafi when he cut off shipments in the early 1980s.

Apart from Libya, some of the IRA’s weapons came from the US during the 1970s, although shipments largely ceased from the mid-1980s.

The main gun-running in the US was controlled by a veteran republican network, whose operation was broken up in the mid 1980s following the creation of a wing of the FBI dedicated to targeting Irish paramilitaries.

The supply was further diminished when the Real IRA, a dissident group opposed to the peace process, splintered from the Provisional IRA in the mid 1990s, taking some of the stocks with them.

"We simply don’t know how much went to the Real IRA," said Mr Boyne. "The security services have made their estimates based on intelligence, and that is the best they can do."

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