Lebanese authorities are questioning a suspect about the killing of Private Seán Rooney.
The 'main shooter' was handed over by the military group Hezbollah, according to the AFP news agency. He is now being questioned.
Private Seán Rooney (24) was among eight Irish Defence Forces personnel who came under attack while travelling in convoy to Beirut Airport on December 14th.
He was killed instantly, while fellow Irish peacekeeper Trooper Shane Kearney suffered head injuries in the attack and was flown home to continue medical treatment in Ireland.
He was transported back to Ireland by air ambulance last week and is now under the medical care of staff at Beaumont Hospital in Dublin.
Three separate investigations are underway into the incident including one by the UN and another by the Defence Forces.