New light should be shed this weekend on whether private diaries kept by Sir Roger Casement were forged by British intelligence to smear him after he was condemned to death for high treason.
The Taoiseach is to open a two-day symposium organised by the Royal Irish Academy in Dublin. The idea, says Mr Patrick Buckley, the academy's executive director, is "to rescue Casement from being a peripheral figure".
Most historians now believe the "black diaries", which detailed Casement's homosexual activities, were genuine, though documents released at the Public Record Office make it clear that Whitehall and the security services used them to foil a campaign to save his life.
One of those who believes they were forged is Mr Angus Mitchell, who has been awarded a grant from the Irish Peace and Reconciliation Fund to complete his research.
Mr Mitchell, who is pressing for an independent forensic examination of the diaries, believes they could have been forged by Admiral Reginald "Blinker" Hall, the head of naval intelligence.
The admiral was later instrumental in leaking the forged Zinoviev letter to help bring down the Labour government in 1924. Hall was one of those who circulated the Casement diaries.
Though security sources insist there are no more hidden documents, 13 pages of MI5 files released last year on the Casement case were withheld.
Casement, a British consul in Africa and South America, was knighted for his work in exposing the exploitation and slaughter of Africans and South American Indians.
He was arrested on a beach in Co Kerry, three days before the 1916 Easter rising, after landing in a boat which had picked him up from a German submarine. A trawler accompanying the submarine and carrying 20,000 guns was scuttled after being intercepted.
Documents released at the Public Record Office in 1998 show that Casement knew the Easter Rising was doomed to failure after Germany reneged on its promise to send troops to help the rebels.
Casement told his MI5 interrogators he had been let down by Germany but unless he accepted what he called its "wholly futile scheme" - the supply of a limited amount of weapons - he would be "branded by his friends in Ireland and America as a coward and traitor to their cause".
"I have done nothing dishonourable, as you will one day learn . . . I came . . . knowing that you were bound to catch me," he told Frank Hall, a senior MI5 officer, and Sir Basil Thomson, Scotland Yard head of CID.
According to the documents, Casement told Thomson that "when he knew the Germans had refused to send men, he felt it his duty to come and warn the rebels a rising would be hopeless".
Whitehall was deeply concerned about a campaign for clemency by prominent figures, including Sir Arthur Conan Doyle, George Bernard Shaw, Joseph Conrad and T.E. Lawrence.
Casement was hanged in Pentonville Prison on August 3rd, 1916.