Clerics involved in investigating child sex abuse were bound to secrecy so the Catholic church's "good name" could be protected, a former primate of Ireland has claimed.
Cardinal Sean Brady, who resigned on age grounds last year, was giving evidence to the Historical Abuse Inquiry (HIA) in Banbridge, Co Down.
He said: "These were unspeakable crimes.
"There was a confidentiality resting upon us too."
The Cardinal faced fierce criticism after it emerged he had attended meetings where two teenage victims of paedophile priest Father Brendan Smyth were sworn to secrecy in 1975.
He added: "There was a shroud of secrecy and confidentiality with a view not to destroying the good name of the church.
"The scandal that somebody who was ordained to serve people should so abuse the trust for their own pleasure was appalling and it was.
"To offset that, the scandal was kept a secret - very, very secret.
"Everybody involved would be bound to secrecy too."
The evidence from Smyth's victims was never handed over to police, allowing the west Belfast churchman to continue abusing children before he was finally jailed in 1994.Tweets by @RBlackBT
On reflection, the Cardinal conceded the secret church inquisition would have been intimidating for a 14-year-old and that some of the 30 questions posed were "inappropriate".
He said he was motivated by an anxiety to stop the sex offender but acknowledged that little or no consideration was given to the impact on the victims - instead the focus was on the offending priest.
The Cardinal said: "I have reflected a lot on this. The reasons for such an inquiry would be to assess the impact of the scandal - the scandal being the unspeakable crime being committed against a minor - was to see how that affected their (Smyth's) own life, a life of faith and morals."
Retired judge Sir Anthony Hart is leading the HIA probe, one of the UK's largest inquiries into physical, sexual and emotional harm to children at homes run by the church, state and voluntary organisations.
One week was set aside to deal with the activities of Smyth and to examine whether systemic failings allowed him to get away with his crimes for so long.
The serial child molester frequented Catholic residential homes and groomed children in family settings after befriending their parents.
Instead of reporting him to the civic authorities Smyth was moved between parishes, countries and even continents where he continued to target children. The only sanctions imposed were temporary bans on hearing confessions and celebrating mass.
Many of Smyth's victims were present in the courtroom for the hearing.
Yesterday the inquiry heard that Gardai in Dublin knew about Smyth's paedophilia as far back as 1973.
Father William Fitzgerald, head of the Norbertine order to which Smyth belonged, also told the panel that the west Belfast priest's poisonous legacy had effectively ruined them.
Earlier it was revealed Smyth had told a doctor in 1994 that the number of victims he sexually assaulted could run into the hundreds.
Smyth's abuse has already been described by a number of witnesses who have previously given evidence to the inquiry.
This week's module has been concentrating on an examination of what opportunities there were to prevent him carrying out the abuse of children and whether any action, or inaction, amounted to systemic failings.
The inquiry was formally established in January 2013 by the Northern Ireland Executive.