Two men in their 30s from Patrickswell, Co Limerick, were detained yesterday under Section 30 of the Offences Against the State Act.
Gardai stressed that they were not suspects in the investigation into the murder of Det Garda Jerry McCabe in Adare, Co Limerick.
More than 20 people have been detained and questioned since the murder. Gardai believe that the men whom they are anxious to speak to are members of the Munster Provisional IRA unit and they are still in the country.