He said that neither Cardinal Parolin nor a host of other Vatican officials had replied, but that when he had brought up the subject with Cardinal McCarrick’s replacement in Washington, Cardinal Donald Wuerl, “it was immediately clear to me that he was fully aware of it.”

Ed McFadden, a spokesman for Cardinal Wuerl, disputed that account on Sunday. “In spite of what Archbishop Viganò’s memo indicates, Cardinal Wuerl did not receive any documentation or information during his time in Washington regarding any actions taken against Archbishop McCarrick,” Mr. McFadden said.

Some survivors of clerical abuse called the allegations a distraction.

“This is infighting between curia factions that are exploiting the abuse crisis and victims of clergy sexual abuse as leverage in the struggle for church power,” said Peter Isely, a survivor. “The sexual abuse crisis is not about whether a bishop is a liberal or a conservative. It is about protecting children.”

The controversy over the allegations is expected to grow in coming days, especially as Francis has declined to deny it.

Instead on Sunday’s flight, he blamed the media for promoting an “atmosphere of guilt” around suspected clerics and shared that until his visit he “had never heard” about Ireland’s notorious mother and baby homes, where children were ripped away from unwed mothers.

He also sought to strike the same conciliatory tone that hundreds of thousands of faithful heard earlier in the day as he began a Mass at Phoenix Park in Dublin by explicitly asking forgiveness for the church’s sins and abuse.

“Some members of the hierarchy didn’t own up to these painful situations,” he said at the Mass. “And kept silent.”