Mr Helmut Clissmann, who has died in Dublin, was the bestinformed German about Ireland and the IRA during the second World War. The Nazis twice failed to smuggle him into Ireland to act as an intelligence agent and link with the outlawed IRA.
Mr Clissmann first came to Ireland as a young student in the 1930s. He studied in Trinity College, worked on a doctoral thesis on "The Wild Geese in Germany", and just before the war was sent again to Dublin as representative of the German Academic Exchange.
During these stays, he made contact with the then illegal IRA and married Budge Mulcahy, who was from a strongly republican family in Co Sligo. He also became friendly with the writer Francis Stuart.
When war broke out in 1939, Mr Clissmann was ordered, along with other Germans living in Ireland, to return to Germany. This was later seen by the German intelligence services as a bad mistake, but they tried to use his expert knowledge to find out the strength of the IRA and whether Germany could use it to launch guerrilla attacks and sabotage in Northern Ireland.
Mr Clissmann also played a role in the release of Frank Ryan from a Spanish jail where he was under sentence of death for fighting on the republican side in the Civil War. Mr Clissmann knew Ryan as an IRA activist when in Ireland.
The first attempt to send Mr Clissmann back to Ireland was Operation Lobster in August 1940, when a Breton trawler was to land him and a radio operator in Sligo Bay. With the help of IRA contacts, they were to travel to England and prepare for the planned German invasion. The German skipper, Christian Nissen, decided to abort the mission, however, after a storm disabled the engine off the west coast.
A year later, Mr Clissmann was involved in Operation Sea Eagle in which a German seaplane would land on Lough Key, Co Roscommon, to let him, Frank Ryan and a radio operator get ashore in a rubber dinghy. Mr Clissmann would bring £40,000 to the IRA and encourage it to become active in Northern Ireland while Ryan was to try to persuade the Taoiseach, Eamon de Valera, to co-operate with the IRA instead of interning and executing its members.
Admiral Canaris, head of the German Abwehr intelligence service, called off Operation Sea Eagle before it got under way.
When the war ended Mr Clissmann, who had also served in the army, was first a prisoner of war, but when his intelligence activities became known to the Allies he was handed over to British intelligence for interrogation about his involvement with Ireland. He claimed to the author Robert Fisk that he was beaten to force him to reveal his Irish contacts.
His wife, who had returned to Ireland after the war, got Mr Clissmann an Irish visa in 1948 with the help of Sean MacBride, then Minister for External Affairs and a friend of her husband.
Irish Army intelligence was wary of Mr Clissmann and his IRA contacts, but his political connections helped him to get Irish citizenship and he eventually became a very successful businessman.
Carol Coulter writes: After the second World War, Mr Clissmann lectured in German in Trinity College and was appointed by the German Exchange Service to assist with exchanges of students, lecturers, authors, musicians and others involved in culture. The Goethe Institute in Munich also appointed him as a teacher of German in Ireland.
He then became a businessman, setting up an agency to import pharmaceutical products, which is now carried on by his sons. He was a founding member of what is now the Irish Pharmaceutical Healthcare Association.
However, Mr Clissmann will be remembered as one of the founders of the Irish section of Amnesty International. He was also one of the main forces behind the setting up of St Killian's German school and was made its honorary president-for-life.
He is survived by his wife, Budge, and children Dieter, Helmut, Maeve, Frank, Alma, Inge and Conn.
Joe Carroll is author of Ireland in the War Years, 1939-1945