Was Narrow Water probe doomed from the start?
IRA bombers behind the Army's single greatest loss of life may have escaped justice because gardai failed to investigate. Alan Murray reports
How the RUC investigation into the Army's biggest single loss of life here was stymied is expected to be revealed in Dublin this week.
A former senior RUC detective is expected to tell the Smithwick tribunal that his investigation into the 1979 Narrow Water bombing was doomed because the Garda refused to provide help and gather evidence.
A fortnight ago, another former RUC officer - 'Witness 69' - told the tribunal how he discovered that the crime-scene on the southern side of the border - from where the IRA detonated two massive bombs - had been destroyed overnight, in spite of a Garda assurance that it would be preserved for detailed forensic examination.
Eighteen soldiers died in the double-bombing, but in spite of two IRA men being arrested by gardai in the Republic shortly after the attack, no evidence was provided to the RUC on which to prosecute them.
Dr Alan Hall, an explosives expert who became director and chief executive of the Northern Ireland Forensic Science Laboratory, also told the tribunal he was "astounded" when he returned to examine the scene south of the border.
" I was expecting to find the scene as I had left it the previous day, but the complete area had been obliterated," he told the tribunal.
"It appeared to me as if someone with a scythe had gone over an extended area and scythed everything to the ground."
Dr Hall said he'd never seen the scene of an incident treated that way before and agreed that he felt an opportunity for him to investigate the scene had been denied him.
This week, the former senior RUC detective directly involved in the investigation of the bombing is expected to tell the tribunal of meetings he had with senior Gardai.
The evidence expected to be given is thought to contain details about the meetings and of difficulties that arose between the two forces during the investigation.
Sixteen of the soldiers killed were members of the Parachute Regiment, travelling in a convoy of trucks from the Ballykinler Army base to a base in Newry.
Their route took them along the shoreline of Carlingford Lough, where an 800lb bomb had been hidden on a trailer.
The initial blast killed six soldiers. When survivors took cover, a second concealed bomb was detonated half-an-hour later, killing 12 more soldiers.
The attack on 2 Para was the IRA's most successful strike against the Army and came seven years after the regiment was involved in the Bloody Sunday deaths in 1972.
Over the years, senior RUC officers have hinted that their investigation was frustrated by the Garda, who released two wanted IRA men - including the suspected bomber,Brendan Burns, now dead - without charge and later destroyed the motorcycle they used to flee the detonation point.
But, because of political sensitivities and the need for the two forces to achieve greater co-operation during the 1980s to combat the IRA, all talk of the Narrow Water investigation being stymied was taboo.
However, the Narrow Water attack has now been introduced into the Smithwick tribunal. This week's evidence is expected to provide more details about the difficulties RUC officers faced in probing the double-bombing with their Garda counterparts and how their investigation was "doomed" from the start.
The Smithwick tribunal was set up to probe alleged Garda collusion with the IRA in the ambushing of RUC officers, Chief Superintendent Harry Breen and Superintendent Bob Buchanan, after they left Dundalk station following a meeting in March 1989.