Published Monday, 02 December 2013
David Black died in an ambush on the M1 last year. (© PA)
The suspects, aged 51 and 34, were detained on Monday during searches in counties Cavan and Leitrim, linked to dissident republican activity.
Mr Black, a 52-year-old father of two, was shot dead on the M1 motorway near Lurgan in Co Armagh as he drove to work at Maghaberry Prison on 1 November, 2012.
A statement from Gardaí said: "The two men, one aged 51 and one aged 34, have been arrested under Section 30 of the Offences against the State Act, 1939 and are being detained at Garda stations in the Cavan area. The men can be detained for up to 72 hours."
© UTV News