The Irish Government is committed to bringing forward new legislation if required to ensure it can assist a public inquiry into the Omagh bomb, a representative has said.

Ruairi de Burca, director-general at the Irish Department of Foreign Affairs, told the first public hearing of the Omagh Inquiry that he was present on behalf of his Government to signal in the “clearest terms our commitment to facilitating and supporting the work of this inquiry”.

The hearing of the inquiry, which is probing whether the dissident republican bomb attack could have been prevented, took place on Tuesday at the Strule Arts Centre in Omagh, Northern Ireland.

Some 29 people, including a woman pregnant with twins, were killed and scores of others were injured in the 1998 atrocity carried out by dissident republican group the Real IRA.

It has been contended that the terrorists prepared the bomb in the Republic of Ireland and also fled back across the border after planting it in Omagh on August 15 1998.

The inquiry into the atrocity was ordered last year by former secretary of state Chris Heaton-Harris following a legal challenge by a bereaved family.

High Court judge Mr Justice Horner, in a judgment, directly recommended that the UK Government carry out an investigation into alleged security failings in the lead-up to the atrocity.

While having no jurisdiction to order the Irish Government to act on the matter, the judge urged authorities there to establish their own probe in light of his findings.

Earlier this month, the Irish Cabinet formally agreed to provide assistance to the inquiry.

In his opening statement, Paul Greaney KC, counsel to inquiry chairman Lord Turnbull, said it is “highly likely, if not inevitable, that the state authorities within the Republic of Ireland hold evidence and bearing upon the inquiry’s terms of reference”, adding that access to materials and citizens requires Irish co-operation.

He said inquiry staff have held a number of meetings with Irish Government officials and the Irish police, and commended “positive discussions”.

“The discussions that have taken place have been positive, and, during them, the Government of Ireland has expressed a strong desire to co-operate fully with the inquiry,” Mr Greaney said.

“The challenge is to see the engagement that has occurred to date translated to meaningful engagement with the inquiry’s processes, both leading up to and during the course of inquiries or evidence hearings.

“We emphasise that the inquiry team does not doubt that the Government of Ireland has a strong commitment to achieving that vital aim.”

He added: “The intention of the inquiry is to ensure that those discussions now move into a practical phase in which clear written agreements are put in place, to make certain that the inquiry has full access to any potentially relevant materials held by the state authorities in the Republic of Ireland, and that it has the ability to obtain statements and call witnesses to attend the inquiry, to give evidence in person.”

Mr de Burca said it is important that the Irish Government is represented, adding that it recognises the importance of the inquiry for victims and survivors of the “heinous attack”.

He also paid tribute to the “unwavering courage and dignity” of the bereaved families “throughout their long quest for truth, justice and accountability”.

“Today we want to assure the families and survivors of the Omagh bombing – unequivocally – of that commitment to fully assist the inquiry,” he said.

“Our commitment is to ensure that there is nothing left unanswered in our jurisdiction at the end of the inquiry,” he said.

“It will be important to ensure the arrangements underpinning our engagement are legally robust and the Government of Ireland is committed to putting in place the most effective possible arrangements to help the inquiry’s work.

“We will do everything in our power to ensure that this spirit of co-operation endures. This will be grounded in law to support concrete action.

“The Government is committed to put in place additional new legislation, if that is what is required, to support our assistance to the inquiry.

“These important details are being worked through with the inquiry team, to ensure that our engagement proceeds on the strongest possible footing.”

He added: “We will work to ensure that our deeds match our words in respect of this inquiry.”

Speaking outside the hearing, solicitor John McBurney, who acts for a number of bereaved families, described the statement from the Irish Government as a “preliminary step” and said that, with public hearings next January, there needs to be quick movement if new legislation is to be brought.

He reiterated the belief that the car for the bomb was stolen in Ireland, and that the device was made in Ireland before being transported to Omagh.

“It seems so obvious. It seems the starting place and point, and it remains to be seen how that is going to be resolved,” he said.

“Otherwise we will get half the picture, and half a picture is not what the families want.

“They want to see it all, they want the truth of it all, and, wherever this takes us, it takes us, because this is the first day of a long journey.”