Joshua Molloy was incarcerated along with two other British citizens while crossing the border with Syria
The Irish father of one of the three men freed from jail in northern Iraq, has compared the occasion to the feeling of waking up on Christmas morning.
Joshua Molloy, from Ballylynan, Co Laois, a former Royal Irish Regiment soldier, was incarcerated along with two other British citizens after crossing a border with Syria.
The three had previously spent a number of months fighting against ISIS in Syria but had decided to return home when they were captured.
They were imprisoned for about 10 days by authorities from the Kurdish Regional Government and it is understood demands had been made for $15,000 (€13,363) in fines to be paid to secure their release.
Reports say Molloy and the others were freed last night, with Ireland's Foreign Affairs Minister Charlie Flanagan first to inform the Molloy family of the development.
Responding to the good news, Joshua Molloy's father Declan, said:
"We are all delighted here. We are jumping with joy to know that he is out. You know that Christmas morning feeling, it's a bit like that, when you find your most sought-after present under the tree, the dream present. That's how we feel."
Mr Molloy's father, a passionate amateur astronomer, even contemplated selling his set of telescopes in order to generate enough funds to pay for his son's freedom.
"It was a tough battle but I have got to give my thanks to Mark Campbell in the Kurdish support group in London."
Declan Molloy added that his son travelled to Syria last year for humanitarian reasons only, and not to engage with the activities of freedom fighters.
It is understood Mr Molloy is in a hotel making travel arrangements out of Kurdistan and is considering spending time in Europe with fellow foreign fighters before he returns to Ireland.
Meanwhile, a UK Foreign and Commonwealth spokeswoman also confirmed the release of the two Britons.