The remains of St Nicholas of Myra, who lived in the 4th century and was the bishop of Lycia, are thought to have been brought by returning crusaders to Jerpoint Abbey in the county about 800 years ago, according to reports.
During his life, Nicholas left anonymous gifts for the poor and his generosity resulted in his canonization after his death in 346.
According to Callan Heritage Society chairman, Philip Lynch, the remains were twice transferred across Europe in the 12th century.
Lynch claims a French family called the de Frainets moved the saint's remains from Myra to Italy in 1169. A relative called Nicholas de Frainet then took the remains to Ireland when his family relocated there and built a dedicated Cistercian abbey to the saint at Jerpoint.
"St Nicholas Church is still standing and there is a slab on the ground which marks St Nicholas's grave," he told the Irish Independent.
"It is an amazing story and yet very few people in Ireland know about St Nicholas's connection with this country. Every year now we get visitors to the site, but still not that many."