The Vatican said on Monday it would launch a promised probe in the autumn into the paedophile priest scandal that has rocked the Irish Catholic Church.
The team will include four "apostolic visitors (who) will set out to explore more deeply questions concerning the handling of cases of abuse and the assistance owed to the victims," the Vatican said in a statement.
The probe, which Pope Benedict XVI announced in March in a landmark letter to Irish Catholics, is intended to help the Irish Church "respond adequately to the situation caused by the tragic cases of abuse perpetrated by priests and religious upon minors," the statement said.
It will begin with the archdioceses of Armagh, Dublin, Cashel and Emly and Tuam, and then be extended to other dioceses, the Vatican said.
A parallel investigation of Irish seminaries will "accompany the process of renewal of houses of formation for the future priests of the Church in Ireland," it said.
The "apostolic visitors" named by the pope are Westminster Archbishop Cormac Murphy O'Connor, Boston Archbishop Sean Patrick O'Malley, and the archbishops of Toronto and Ottawa, Thomas Christopher Collins and Terrence Thomas Prendergast, the statement said.
The Irish Bishops' Conference welcomed news of the investigation, saying it was "one more important step on the path to healing, reparation and renewal in the Church in Ireland" and promising to cooperate fully.
Archbishop of Dublin Diarmuid Martin said it was an "important element" in the process of addressing "the truth of a dark moment" in the history of the Irish Catholic Church.
Two ground-breaking inquiries last year into the once powerful Church shocked the mainly Catholic country.
They found that abuse by Catholic clergy and members of religious orders had been widespread for decades and that there was a culture of secrecy and cover-up designed to protect the reputation and assets of the Church.
Pledging a new "season of spiritual rebirth for religious life" in Ireland, the statement said the investigators would "seek possible improvements to the current procedures for preventing abuse."
It said the probe aimed to "contribute to the desired spiritual and moral renewal that is already being vigorously pursued by the Church in Ireland."
In the pope's March pastoral letter, he expressed "shame and remorse" for the sexual abuse of children by priests and conceded that "serious mistakes" were made by Irish bishops in responding to allegations.
The pope said priests and religious workers guilty of child abuse "must answer" for their crimes "before properly constituted tribunals."
The Vatican has for months been battling a series of sex abuse scandals amid allegations that the Church had protected paedophile priests from prosecution in the United States and several European countries.