Omagh bomb victims' relatives tonight urged the Garda to co-operate fully with the PSNI in the investigation into the attack.
They said their first meeting with senior officers in the Republic was at times "very difficult and frank".
But Mr Michael Gallagher - whose son Aidan was among the 29 people and two unborn babies killed in 1998 "Real IRA" attack - said gardai were left in no doubt of what was expected of them.
Speaking in Monaghan after the four-hour meeting he said: "We have urged both the Garda and the PSNI to co-operate fully.
"What we all want is to see those responsible for Omagh behind bars.
"We were given assurances that they will work to that end."
He said a number of issues were discussed with Assistant Garda Commissioner Kevin Carty and Detective Superintendent Tadhg Foley, many of which could not be aired in public.
Relatives quizzed them about the man alleged to have stolen the car used in the atrocity.
"We did raise that but they described it as an operational matter," Mr Gallagher said.
He said although the officers were restricted to the evidence given in a court of law, he would have liked more information.
But he added: "We left the Garda team in no doubt about what we expected of them.
"It was very helpful to meet the people directing the investigation and let them know of our concern."
The families are trying to raise enough money for their High Court action later this year against the men they claim plotted the attack. It is more than four-and-a-half years since the Omagh bombing, but despite a lengthy investigation on both sides of the border nobody has so far been charged with murder.
PA