Sinn Féin President Gerry Adams has said he totally rejects allegations made in a BBC Northern Ireland Spotlight programme last night that he sanctioned the 2006 murder of former party worker and British agent Denis Donaldson.
Mr Donaldson, 55, a Sinn Féin official and close colleague of Mr Adams, was shot dead at an isolated cottage near Glenties in Co Donegal in April 2006.
He had been living in the remote area following his exposure as a state agent a year before his death.
Mr Adams has said if his legal advisers tell him he has a case against the BBC following last night's programme, he will take legal action.
Speaking on RTÉ's News At One, he "specifically and categorically" denied the allegations made in the programme, describing the allegations as "unsubstantiated" and the programme as "low journalism".
He said he did not see the programme, but received a "read-out" of it this morning.
Mr Adams said he has signed up to a new agreement to deal with legacy issues.
He said British intelligence has "never stopped moving against" him, adding: "This is about stopping the onward development of Sinn Féin".
Mr Adams said he was shocked and surprised to hear of Mr Donaldson's murder.
He said gardaí are following a line of inquiry that Mr Donaldson's murder was the responsibility of dissident republicanism.
The allegation about the 2006 killing of Mr Donaldson was made by a man who claimed he was also a paid state agent in the IRA.
The man made a series of claims, on an anonymous basis, to BBC Northern Ireland.
The most explosive was that Mr Adams sanctioned the killing of Mr Donaldson.
Dissident republican group the Real IRA claimed responsibility for the murder in 2008 but the circumstances surrounding Mr Donaldson's outing as a British agent and subsequent death have long been shrouded in mystery.
The man interviewed by Spotlight said the IRA was responsible for the murder and Mr Adams sanctioned it.
Mr Adams's lawyer told the programme his client had no knowledge of or involvement in Mr Donaldson's death and denied being consulted about it.
His party colleague Gerry Kelly dismissed the documentary as a "collection of discredited conspiracy theories".
"The programme makers have had no regard for the feelings of families of the victims of the conflict, including the family of Denis Donaldson," said the North Belfast Assembly member.
Speaking on RTÉ’s Today with Sean O’Rourke, Mr Kelly said the claim was made anonymously and that a garda investigation into the case has said "something different".
Mr Kelly said that the 40 years that Mr Adams has given the people of Ireland should "stand over a single programme".
He added that people are being asked to believe someone who is a "paid informer" as opposed to someone who has been around for a long time and the evidence of a garda investigation.
Asked about the allegations, Taoiseach Enda Kenny this morning said there are issues about Mr Adams's past that he should answer.
