The Minister for Justice will order an inquiry into the 1970 Arms Trial if the Government's current investigation does not prove sufficiently conclusive.
A spokesman for the Minister said yesterday that Mr O'Donoghue had not ruled out a wider investigation. If necessary, he would direct the Oireachtas Committee on Justice, Equality, Defence and Women's Rights to begin an inquiry.
The Minister was satisfied that certain questions were raised in last week's Prime Time programme on RTE, the spokesman said. He added that Mr O'Donoghue had made inquiries of the Garda, the Chief State Solicitor's Office and the Attorney General's Office.
Officials from the Attorney General's Office examined files relating to the Arms Trial in the National Archives late last week as part of the Government's inquiries.
It has already been established that, contrary to normal procedures, the book of evidence in the case was prepared by gardai supervised by members of the prosecution's legal team rather than by the Chief State Solicitor's Office.
Mr O'Donoghue's spokesman said that the Minister wanted the inquiries to be completed as quickly as possible and to establish the truth of what occurred 31 years ago.
It is understood that the Minister believes a thorough investigation is needed into this critical period and that he wishes to establish whether certain individuals got a "fair deal".
"On the basis of what has been established to date, questions have certainly been raised", the spokesman said.
The Taoiseach, Mr Ahern, said in the Dail last week that he would examine whether the archive of the inquiry of the Public Accounts Committee 30 years ago into the Arms Trial could be released.
The Fine Gael leader, Mr Michael Noonan, pointed out that the "very lengthy and aborted" inquiry by the committee had produced an enormous archive. There was no procedure for the Dail to access this information, which was not subject to the 30-year rule.
An Oireachtas spokeswoman said yesterday that the relevant files were in the Leinster House vault.
Mr Ahern told TDs that he would see if the material could be made public through an order of the Dail under the National Archives Act. A more detailed report would be given as soon as the Dail returned after the Easter recess.
A Labour Party spokesman said that, while awaiting Mr O'Donoghue's report on the Arms Trial, the party considered that there was a strong case for an independent investigation outside the Oireachtas.