An inquiry which forces paedophile priests to give evidence could take up to two years to establish, the North's First Minister said Tuesday.
Most victims want a statutory investigation with full powers to compel witnesses but there may be a significant delay, Peter Robinson said.
The Executive is considering ordering an investigation into the extent of child abuse in Catholic church and state-run institutions in Northern Ireland. It followed the Ryan Report that uncovered decades of abuse in some institutions in the Republic.
Mr Robinson told the Assembly: “If we have to bring forward legislation it could be 18 months to two years before we would be proceeding.”
He said there was a possibility of combining some statutory and non-statutory elements.
“If we take the statutory route, the only statutory provision available for us at the present time would limit the period of an inquiry to between 1973 and 1989, and I do not think that is going to assist victims,” he said.
An alternative is to draw up fresh legislation, but that could take a significant period of time, Mr Robinson added.
Martina Anderson and Jonathan Bell, junior ministers at the Office of the First Minister and Deputy First Minister, have met officials responsible for historic abuse inquiries in the Republic and Scotland.
The Executive Taskforce on Historical Institutional Abuse held meetings in Armagh, Belfast and Derry in March.
The Executive announced in December it would hold an inquiry and the taskforce is considering what its nature should be.
Mr Robinson added: “It is important that if we have a statutory inquiry that the statutory element of it does not increase the pain that victims have already gone through. In many cases, if they have to give evidence and be cross-examined, that may well do it and we cannot really have a statutory inquiry where the only person who was obliged to come and to give evidence and to be cross-examined is the person who is accused.”
Margaret McGuckin, who leads the Survivors and Victims of Institutional Abuse group, said members wanted speedy action and warned many people did not have two years to spare.
“It is important that we have a statutory inquiry or else that would mean that they are getting off the hook, as simple as that - this would all just come to nothing.”
SDLP MLA Conall McDevitt acknowledged the work the Office of the First Minister and Deputy First Minister had carried out already.
“It is about getting it right rather than getting it quickly. The needs of survivors will ultimately only be able to be properly met, albeit over a longer period of time, if we have a fully independent, statutory-based inquiry,” he said.