The Taoiseach confirmed that he had received a letter from a person offering to give sworn evidence to a tribunal of inquiry relating to the payment of £30,000 to the Minister for Foreign Affairs, Mr Burke.
Mr Ahern said: "This was considered by me in the light of the facts as then known to me and also in the light of the fact that the individual had not then and, as I understand it, has still not signed a statement of complaint for the gardai. In these circumstances no action by me was warranted at that time.
"In the meantime, other matters came into the public domain, particularly the letter from Mr Michael Bailey of Bovale Developments to Mr James Gogarty of Joseph Murphy Structural Engineering Ltd, and also the letter from Messrs Donnelly, Neary & Donnelly, solicitors, to which I referred earlier today in the House.
"These matters give rise to concern as to the operation of the planning process in north Co Dublin over a number of years. It is for this reason that the Government has decided that a new tribunal will be established to investigate all matters relating to the parcels of land referred to in Mr Bailey's letter and any related matters.
"The terms of reference have been the subject of discussion between the whips and the formal motion will be put down for debate when these discussions are completed."
The Taoiseach, who was replying at Question Time to Mr Pat Rabbitte (DL, Dublin South West), said he understood that the administrative work involved in the setting up of the Moriarty tribunal was well advanced.
It had been greatly assisted, he added, by the Government's decision that the administrative team which so capably assisted Mr Justice McCracken in his work in the Dunnes payments tribunal should remain in place and serve the new tribunal.
"The fact that the new tribunal will use the same premises in Dublin Castle should also expedite its commencement. All necessary resources will be provided to enable the tribunal to set about its inquiries and there will be no administrative impediment to it commencing its work."