The Government has no intelligence as to who murdered former Sinn Fein official-turned-British agent Denis Donaldson, Taoiseach Bertie Ahern said today.
As he unveiled, along with British Prime Minister Tony Blair, the Governments' plan for securing a power-sharing government in Northern Ireland, Mr Ahern insisted everything was being done to catch whoever shot Mr Donaldson in a remote cottage near Glenties, Co Donegal.
Mr Ahern said: "The Minister for Justice Michael McDowell and the gardaí have already made it absolutely clear that they will carry out an intensive investigation to try and find out who perpetrated this terrible death.
"We have no intelligence, no information, to indicate whether, as I said in the Dail, it is retribution for some past event or some falling out along the way or whether it is some dissident group.
"We don't know and we will do everything we can to try and find that out. It is important to do so in any murder but I think it is important in this one also," he said.
Gardaí today resumed their examination of the scene of the murder.
Postmortem results released last night show he died of a shotgun wound to his chest.
He also suffered a number of other gunshot injuries, including having his right hand nearly severed.
Members of the Garda Water and Dog Units are joining the search for evidence today.
The former Sinn Féin official (55) moved to Co Donegal after admitting in December that he had been a British agent for 20 years.
Garda sources have said they believe the murder was carried out by more than one person, most likely republicans who carefully planned their operation. However, the possibility that some of Donaldson's former British intelligence handlers were involved was also not ruled out.
Senior British and Irish government sources said there is no evidence that the murder was "authorised" by the IRA leadership. The IRA said in a statement on Tuesday it was not involved in the killing.
Northern Ireland Secretary Peter Hain said this morning he believed Mr Donaldson was killed by dissident republicans.
He dismissed claims that the British security services were behind the murder as fanciful and desperate. "It is much more likely to have been a dissident republican of some description than anything else."
Yesterday, the Taoiseach told the Dáil that Mr Donaldson was warned by gardaí in January that his life may be in danger and that his house was routinely checked by officers.
Mr Ahern said he was last seen by gardaí in Glenties at 5pm on Monday, about 24 hours before he was found murdered in his remote cottage.