Two brothers have escaped from Castlerea Prison in Co Roscommon overnight, the Prison Service has confirmed.
The two, who are of Romanian origin, were serving sentences after being found guilty of stealing from parking meters in Galway.
Both were due to be released next April and one of the brothers had received a letter notifying him of a decision from the Department of Justice that he should leave the State.
The brothers, aged 23 and 29, were last seen in the Grove area of the prison at 11.30pm last night, but were reported as "unaccounted for" at 6.30am this morning.
The Prison Service would not comment, but it is understood the men left a note saying that they could not stay in the prison.
A search is under way and prison authorities are also trying to establish how they managed to escape.
The Grove is surrounded by a wire fence and Castlerea Prison is surrounded by high walls.
Minister for Justice Alan Shatter suggested the two may have had assistance from the outside, but he said he is awaiting a full report on the matter.