Kingsmills families have expressed their disappointment at the Irish government’s failure to deliver on a promise to victims’ loved ones.
At Monday’s latest inquest hearing, the court was told not all material from An Garda Siochana had been disclosed to the legal parties.
Taoiseach Enda Kenny vowed in 2015 that all Garda files related to the murders of 10 Protestant workmen in 1976 would be handed over.
Colin Worton, brother of Kingsmills victims Kenneth, said: “The families are bitterly disappointed that the southern government have still not handed these files over.
“The taoiseach looked us in the eyes at Bessbrook and promised us that anything they had we would get.
“You can only take that promise at its merits so it seems fairly hollow.”
Mr Worton said if the documents still were not forthcoming political pressure needed to be applied on the Irish government.
He added: “This inquest has taken so long and further delays just add to that frustration.
“My mother is in her 90th year and another of the victim’s mothers was 94 in January.
“Kenneth’s own children are now middle-aged. It’s dragging us all down.”
Coroner Brian Sherrard said he would address the issue of Garda files.
“There is a cross-border element to it (the case) and we would not be able to proceed properly in this matter in the absence of disclosure of this material from An Garda Siochana,” he said.
The coroner also told the hearing one of the most important parts of the inquest could be a ‘weapons linkage chart’ containing information linking the weapons used at Kingsmills to other atrocities and the organisations they were used by.
The preliminary hearing was further told statements were also due to be submitted by the police and Ministry of Defence as well as Sean O’Callaghan, former Provisional IRA member turned Garda informant.
For each statement it was necessary to agree how much of the material needed to be redacted.