POLICE have arrested two men in connection with the murder of Cookstown prison officer David Black.
The 31 and 44 year-old were detained in the Lurgan area in County Armagh on Friday morning.
One of them is the prominent republican, Colin Duffy.
Both have been taken to Antrim police station for questioning.
Mr Black, a father of two from the Orritor Road area of the town, was killed on a stretch of the M1 motorway on his way to work at 7.30am this morning.
His car veered into a ditch after a car with a Dublin registration plates drove up beside him and fired a number of shots.
The car was later found burned out at Inglewood, Lurgan, County Armagh.
Mr Black was a well known member of the Cookstown community who had been involved in a number of community and charity projects in the area. He was a very experienced officer, close to retirement, who had worked through the Troubles.
Police are investigating a link between the attack and a burnt-out car found in Lurgan, County Armagh.
Mr Black, a father-of-two, was the first prison officer to be murdered in Northern Ireland in almost 20 years. The Police Service of Northern Ireland (PSNI) have said they believe dissident republican paramilitaries were responsible for the attack.
The murder has been condemned by all political parties in Northern Ireland.