The Libyan government supplied the IRA with the majority of its weapons
Links between the IRA and Libya can be traced back to 1972 when the country's leader Colonel Muammar Gaddafi first praised the group as allies in a struggle against Western imperialism.
Gaddafi later helped provide the IRA with the weaponry they needed to wage an armed campaign which lasted more than 30 years and claimed more than 1,000 lives.
It is not known when the first arms shipments began, but the relationship became public knowledge in March 1973 when the Irish Navy boarded a ship called the Claudia, off the coast of County Waterford.
They found five tonnes of weaponry supplied by the Libyan government. Veteran IRA man Joe Cahill was also on board.
The IRA's relationship with Tripoli intensified in the 1980s, particularly after 1986 when American planes, stationed in the UK, took part in a bombing raid on Libya.
2 tonnes of Semtex
20-30 heavy machine guns
7 Surface-to-air missiles (unused)
7 flame throwers
11 rocket-propelled grenade launchers
90 hand guns
Source: Security estimates/Jane's Intelligence Review
More than 100 people died in the attack, including Hanna Gaddafi, the adopted baby daughter of the Libyan leader.
Colonel Gaddafi said he resumed contact with the IRA in the aftermath of these air raids.
A year later, another boat was stopped on its way to Northern Ireland.
The Eksund was carrying around 1,000 AK-47 machine guns, a million rounds of ammunition, more than 50 ground-to-air missiles and two tonnes of the powerful Czech-made explosive, Semtex.
However other smuggling runs had already been successful.
Semtex supplied by Libya became the IRA's most devastating and infamous weapon.
The plastic explosive was first made in Czechoslovakia and is virtually odourless, easy to use and, unlike home-made bombs, stable.
The IRA began using it to create landmines for attacks against soldiers in border areas.
But instead of using up supplies as a primary explosive, the IRA used Semtex as a "booster" for large home-made bombs.
BBC political editor Mark Devenport said a source with access to high grade intelligence said there was no question that Libyan arms had greatly enhanced the IRA's deadly force and transformed their ability to mount a wide range of operations.
He said the expert provided him with a catalogue of attacks carried out with Libyan Semtex.
These included the Enniskillen bomb in 1987 which killed 11, the Ballygawley bus bombing in 1988 which killed eight soldiers, the mortar attack at Downing Street in 1991 when the IRA tried to wipe out John Major's Cabinet and about 250 other booby-trap bombings.