Relatives of the McGurk's Bar bombing - one of the worst atrocities of the Troubles - have presented new evidence which they claim shows the Government and RUC were prepared to lie to Dublin about the bombing.
The 1971 explosion in Belfast killed 15 people and was initially described as an IRA 'own goal', but was later proven to be a UVF attack.
Relatives of the victims have insisted a deliberate campaign of disinformation was started by the RUC and British Government in order to point the finger of suspicion at the victims inside the bar instead of those responsible.
Yesterday, researcher and family member Ciaran MacAirt was among those who travelled to Dublin to present new evidence to the Dail's Justice and Equality Committee.
He said the new information came from a European Commission of Human Rights report that examined internment and allegations of torture in the early 1970s.
"Part of that report asked the British Government why the internment policy was so discriminatory against Irish Catholics," said Mr MacAirt.
"Until 1973, no members of the Protestant community had been interned, even though we now know Protestant extremists had killed 120 civilians."
Mr MacAirt explained that within the report, two statements - from George Shillington, Chief Constable of the RUC in 1971, and Harry Tuzo, commander of the Army in Northern Ireland - denied any loyalist violence existed in 1972.
"We now know that to be bunkum," he said.
For the report the Irish government had provided a schedule of atrocities, where they listed incidents they believed to be caused by loyalist extremists.
"One of those was the McGurk's Bar bombing. Within the report, the RUC and the British state refuted the central finding and said the McGurk's Bar bombing was an IRA own goal and the bomb was in transit towards a hotel," said Mr MacAirt.
"That's disinformation, but the fact they said there was a target of a hotel is a new lie.
"It's information not given to us by the Historical Enquiries Team, the Police Ombudsman and by the PSNI.
"It's just been completely made up and fabricated."
He continued: "It's one thing for our society to be misinformed by the state, but the Irish government and European Commission were also hoodwinked as well."
Mr MacAirt said the presentation received cross-party support from the committee members, comprising representatives of Fine Gael, Fianna Fail, Sinn Fein and independents.
At present the families are engaged in a legal action against the Chief Constable of the PSNI, George Hamilton.
They are seeking new inquests for the family members and to quash a report from the Historical Enquiries Team.
The next sitting of the case is due to take place on Monday, February 27.
In 2011 a report by the Police Ombudsman, stated there was bias in the original RUC investigation into the McGurk's Bar tragedy. This was later reversed by the Historical Enquiries Team report.
Last year the Chief Constable again changed the official PSNI position, saying he accepted there was bias.
"If a false line of enquiry equates to investigative bias, on that basis I am accepting the language that the Ombudsman chose to use to present that (initial RUC) hypothesis that turned out to be incorrect," he said.