Both the Garda and PSNI must lend their support to the Omagh victims' Stg£10 million civil action against the suspects if anyone is ever to be convicted for the atrocity, it was claimed today.
Mr Michael Gallagher said relatives felt enormous relief now their landmark lawsuit had finally got off the ground, over five years since the Real IRAbombing.
But he urged authorities on both sides of the border to co-operate fully with the families' lawyers.
Mr Gallagher, whose 21-year-old son Aidan was one of 29 killed in the August 1998 massacre, also said the Irish and British governments could learn something from the way Spanish authorities dealt with the Madrid bombing.
"Three weeks ago the Spanish government made a statement saying that all the main participants in the Madrid bombing were either dead or behind bars," he said.
"We have to remember the Spanish government knew nothing about those involved prior to the bombing.
"In context with Omagh, where books have been written about the suspects, it proves we have a lot to learn."
He said the relatives had waited patiently for years to see those responsible convicted for murder.
The news that FBI spy Mr David Rupert had agreed to testify against the five suspects had been welcomed with "absolute delight" Mr Gallagher said.
Speaking at the Fine Gael Ard Fheis in Dublin, Mr Gallagher described how the bereaved and victims of the Omagh atrocity had come together, supported each other and, eventually, launched their own civil action.
PA