Historian names IRA mole who revealed location of Cork mayor Tomás Mac Curtain's killer
Lord Mayor of Cork Tomás Mac Curtain was murdered by the RIC on March 20, 1920.
An historian says he has unmasked the identity of an IRA mole in the RIC who informed Michael Collins of the whereabouts of a superior who had organised the murder of Cork lord mayor Tomás Mac Curtain. The superior was later assassinated in the north on Collins' orders.
Jim Herlihy, the country’s foremost chronicler of the RIC, has revealed from extensive research that Collins' spy network was far-reaching and involved a priest who passed messages between a mole in the RIC and Collins.
RIC detective inspector Oswald Swanzy led a party of unidentified men, who broke into Mac Curtain’s home on March 20, 1920, and killed the lord mayor, who was commandant of the IRA’s Cork No 1 Brigade. Soon afterwards, Swanzy left the city.
Seeking revenge for the murder, Collins sought information on Swanzy’s whereabouts from his spies.
He had Swanzy traced to Lisburn with the help of RIC sergeant Matthias McCarthy, then stationed in Belfast, who had helped him in the past.
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“What is not generally known until now is that Michael Collins had another RIC constable recruited as an intelligence officer in the RIC county inspector’s office in Lisburn, which was in the same building as DI Swanzy’s office,” Mr Herlihy said.
It was he who tipped off Collins about Swanzy’s movements and the inspector was assassinated as he left Christ Church Cathedral, Market Square, Lisburn, on August 22, 1920.
Mr Herlihy said the mole was James Gunn.
He started researching James Gunn’s IRA career some years ago after his now deceased son, Patrick Gunn, who was a retired garda, contacted him enquiring about his father’s past.
Gunn was born in Lanarkshire, Scotland on October 20, 1890, but grew up in Holywell, Belcoo, Co Fermanagh, and enlisted in the RIC in Enniskillen on May 15, 1912.
He served in various locations both north and south of the border, before being appointed chief clerk in the RIC Lisburn barracks, where Swanzy came after the murder of Mac Curtain.
Herlihy said Gunn came to greatly embrace the Sinn Féin movement and he became intelligence officer / officer commanding of the 3rd Northern Division of the IRA.
“As such, he was responsible for intelligence work on behalf of Michael Collins. The influence of Fr Terence Caulfield PP at Holywell Church in Belcoo, Co Fermanagh, was a factor. Fr Caulfield was a prominent and forthright devotee of Sinn Féin and played a central role in that organisation in the South Fermanagh area,” Mr Herlihy said.
He said the priest acted as "cover" for the receipt of instructions from Collins to James Gunn and as proof, his son Patrick Gunn was in possession of a 1920 Christmas card and a hand-written letter from Michael Collins dated February 26, 1922.
The correspondence was sent deliberately to the priest and then onto Gunn.
The RIC mole had become increasingly anxious about his position, but Collins urged him to stay put as he was providing him with vital intelligence.
While in Greystones in Co Wicklow in 1922, Gunn went off to meet some men and returned with a gold pocket watch.
It bore the inscription: "To James Gunn, with compliments of the 3rd Northern Division IRA".
Herlihy believes this represented a big thank you from the IRA for all the intelligence Gunn had gathered for them, including information which enabled them to kill the man responsible for the murder of Cork’s lord mayor.
- This article was originally published on June 24, 2025.
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