Published Tuesday, 28 September 2010
The complaint has been made against Father Peter Donnelly, who is a parish priest in Drumaroad near Castlewellan, and dates back to the 1980s.
Parishioners in the diocese of Down and Connor were informed of the development during weekend masses.
Father Donnelly denies the complaint but has voluntarily agreed to relinquish all pastoral duties while the investigation is pursued.
In a statement the Down and Connor Press Office said: "In view of the ongoing police investigation, it would be inappropriate to make any further comment on the complaint at this time."