GARDAI have raided the Dublin home of a man arrested for questioning about the weekend terrorist murder of 25-year-old police constable, Ronan Kerr.
The 40-year-old suspect, who is from county Tyrone, was stopped in a car on the road between Omagh and Ballygawley yesterday morning.
He was being questioned last night about the murder in Omagh on Saturday and the discovery of a significant cache of weapons and explosives in nearby Coalisland on Tuesday night.
Armed members of the Garda Special Branch later searched an apartment used by the suspect in Clarehall on the northside of Dublin but did not seize anything.
But the PSNI seized the vehicle in which he was travelling for a forensic examination.
This was the second arrest made by officers investigating the car bomb attack.
On Wednesday police detained a 26-year-old suspect in Scotland for questioning about the arms find.
He was released yesterday and re-arrested for questioning about the murder.
Both men are being held at Antrim police station.
Police are satisfied that a "freelance" gang of former Provisional IRA men from East Tyrone were responsible for the bomb attack.
The gang have been considering affiliating to the terror group styling themselves as Oglaigh na hEireann, but are continuing to operate as a stand-alone mob of experienced terrorists.
PSNI assistant chief constable Drew Harris said yesterday: "Detectives from serious crime branch who are investigating Ronan's murder have made a significant discovery of arms and munitions -- one of the most significant in recent years."
The weapons haul found in stolen vehicles in garages on the Mountjoy Road in Coalisland included Kalashnikov rifles, ammunition, timer power units, detonators, incendiary bombs, components for rocket launchers and a quantity of explosives, possibly Semtex.