Stop Church Child Abuse welcomed the opening on Monday of the investigation into 13 orphanages and children's homes but said it was now time for the government to roll the inquiry out across Britain.
Jonathan Wheeler, a lawyer who deals with child abuse cases in Britain and a founding member of Stop Church Child Abuse said: "The start of this inquiry will be a relief to the alleged victims, allowing them to take heart in the fact that a process intended to bring them justice is at last under way. Lessons must also be learned by the authorities and all those responsible for the care of young children to prevent this kind of abuse from ever happening again.
"We have been calling for a similar overarching inquiry in England and Wales. The government has refused but if Northern Ireland can tackle the issue, then why should survivors here be denied their say and the proper scrutiny of all they have suffered?"
The historical institutional abuse inquiry will examine claims of sexual and physical abuse, including the Kincora boys home in east Belfast, in which a senior Orangeman and a number of loyalist extremists raped children.
The inquiry may also explore allegations that the security forces, both MI5 and RUC special branch, knew about the abuse in Kincora but failed to act against those responsible because many of the abusers were state agents.
Chaired by the retired judge Sir Anthony Hart QC, the inquiry based in Banbridge court house will hear written and oral testimony from 434 individuals and their stories of abuse in institutions, which range from young offenders centres to orphanages run by Catholic nuns.
It will also investigate how 120 children from these institutions between 1947 and 1956 were sent to Australia as part of a child migration policy at the time. The hearings will last up to June 2015 and could cost
up to £19m.
Most of the applications (280) have come from individuals residing in Northern Ireland. However, there have also been 61 applications from Australia, 63 from Great Britain, 20 from the Republic of Ireland and eight from other countries.
Up to 300 people are expected to turn up in person to give evidence to the inquiry, which was established by the Northern Ireland assembly, following a long campaign by victims of abuse in institutions.
A victims support service has been established through the office of the first minister and deputy first ministers of Northern Ireland to provide support and advice to victims and survivors before, during and after the inquiry.