A heartfelt apology by a bishop criticised in the Murphy Report was never made public, giving the perception he did not express remorse, his funeral Mass was told.
Bishop Dermot O'Mahony wrote to the Archdiocese of Dublin and its Archbishop in 2009 profoundly regretting if any "action or inaction" of his "contributed to the suffering of even a single child".
Bishop O'Mahony died on December 10, aged 80, following a long illness.
His brother, Gerry O'Mahony, told mourners at St Anne's Church, Shankill, Co Dublin, that as his apology was not published, the public never believed he had shown remorse.
"It was something that haunted him to the very end of his life," Mr O'Mahony added.
The Murphy Report into child sex abuse found Bishop O'Mahony had failed to tell the National Rehabilitation Hospital, Dublin diocesan authorities or gardai that Fr Noel Reynolds, who was a chaplain to the hospital, had a problem with child sexual abuse.
Mr O'Mahony yesterday described his late brother as "gentle, deeply spiritual, caring, a great believer in justice and peace and the dignity of man, in particular the handicapped, underprivileged and the voiceless".
"He had a great gift of comforting those who came to him in distress, and they were hundreds if not thousands," he said at the Mass, which was concelebrated by around 90 priests, eight bishops and the Papal Nuncio, Archbishop Charles Brown.
Mr O'Mahony recalled his brother's love for rugby, and made the congregation laugh describing how a picture of Ronan O'Gara hung on the wall of his sitting room "between the pictures of many saints".
Chief celebrant, lifelong friend Fr Tim Murphy said they shared a deep friendship where they could "speak the truth to one another regardless of cost".
He also referred to Bishop O'Mahony's reaction to the Murphy Report.
"It was personally devastating for him. He was the first to say that what he suffered no way equated to the suffering of the innocent, who were traumatised and abused.
"It was his sensitivity to that pain and that suffering that made his personal apology so real and heartfelt."
Fr Murphy said the bishop made important contributions to Church and national life.
As the coffin was carried out of the church, the congregation broke into singing The Bells of the Angelus, and spontaneous applause.
Bishop O'Mahony was ordained a priest in 1960. He was ordained bishop in 1975. He resigned as Auxiliary Bishop of Dublin in 1996 on health grounds.