Families of Omagh bomb victims today met British Home Secretary Mr David Blunkett to complain that co-operation between the two governments in catching the killers was a "mockery".
They told him they felt let down by assurances the two governments and their police forces were working closely together to bring the "Real IRA" bombers to justice.
In a meeting in London, the group aired their greviances over an allegation that the Garda Special Branch failed to pass on to their colleagues north of the border information that might have stopped the bombing.
The victims' families told Mr Blunkett they had intelligence supplied by a serving detective sergeant in the Garda who told them police knew four days before Omagh that an active terrorist unit was trying to acquire a car in which to plant a bomb in Northern Ireland.
This intelligence was not passed to the RUC, it is claimed.
Speaking after the meeting Mr Victor Barker, of Weybridge, Surrey, whose son James (12) was among those killed in the bombing, said of the detective sergeant's information: "What he had to say made a mockery of the apparent commitment to co-operation of both governments".
But Mr Michael Gallagher whose son Aidan was among those killed, said the meeting with Mr Blunkett had been positive. "The [British] government is now aware of our position. It's now up to them to prove to us that they can do something about it".
The allegations are to be examined by a panel of three former senior civil servants, the Minister for Justice, Mr O'Donoghue, confirmed last night.
Sinn Féin president Mr Gerry Adams later called for the findings of the Government-established inquiry into the claims.
Speaking in Dublin he said he welcomed the inquiry, under three former senior civil servants, and appealed for it to be completed urgently.
He said: "It needs to be very transparent. It needs to be speedily followed through."
He said that the findings of the report should "absolutely" be published.
"You cannot have an in-house inquiry and you cannot have the conclusions of an inquiry being in-house. This is a matter of public confidence and it has to be very, very transparent and a matter of public ownership."
He added that the new development was further evidence of the need for an independent Garda Ombudsman.
PA