A year before the outbreak of the second World War in Europe the British and Irish governments co-operated to establish an Irish counter-espionage department under the control of the Irish Department of Defence, according to MI5 files released in London today.
In April 1938, after the then Taoiseach, Mr Eamon de Valera, secured an agreement with the British government to withdraw British garrisons from Irish ports, he sent Mr Joe Walshe of the Department of External Affairs to London to discuss the Government's "desire to set up a department similar to the Security Service". According to MI5, Mr Walshe had reason to believe "there was a good deal going on in Eire that needed attention".
And so with encouragement from the British security service a new Irish counter-espionage department was established under the control of the Department of Defence to report to London and Dublin on German activity in Ireland. Further to the April meeting, officers from the British security service met Col Liam Archer of the Department of Defence, again in London, in October 1938, and Col Archer was duly appointed head of the Irish counter-espionage department. The "Dublin link" between the Department of Defence and MI5 was firmly established by the outbreak of war in September 1939, by which time the two services were in "fairly regular correspondence, which was carried by means of the Irish High Commissioner's bag".
The Dublin link was, therefore, "established at the request of the Eire government and operated with the full knowledge and approval of the British and Eire governments". During the second World War the British secret intelligence service also established a network of informers in Ireland to prevent the leakage of military information to Germany, which at times overlapped with the Irish counterespionage department.
The existence of the Secret Intelligence Service (Irish Section), which reported to MI5, was carefully concealed from the Irish authorities. In an MI5 report on the work of the Irish Section of the Security Service, written in 1946, the author wrote: "It will be realised that this organisation had to be kept secret, not only from the enemy in Eire, but also from the Eire authorities.
"Had it come to the knowledge of the latter, the effect on our political relations with Eire would have been very serious and irreparable harm would have been done to the general security co-operation . . . "