GARDAI are still searching for two IRA members who they believe were involved in the murder of Det Garda Jerry McCabe at Adare, Co Limerick, last Friday.
The search is understood to be spreading from Munster, with IRA safe houses around the country under watch.
Three women and two men detained and questioned about the murder were released without charge yesterday. All are from the Limerick area.
Gardai are hoping to link forensic evidence found in the two cars abandoned by Det McCabe's killers with the IRA gang which, they believe, carried out the murder.
The two men at the centre of the Garda search are both long serving IRA members and regarded as very dangerous.
One is from Co Tyrone and has had links with the IRA units in Dublin and Munster. The other, in his early 40s, is from Dublin originally and has been active in the Munster IRA since the late 1980s.