Pope Francis has refused to respond to claims by a former Vatican diplomat, who has called for him to resign.
Archbishop Carlo Maria Vigano also accused him of covering up allegations of sexual abuse by a US cardinal.
The Pope was asked about the accusations by reporters on his flight back to Rome after this weekend's Papal visit to Ireland.
He said he would not say a single word in response to the 11-page letter from Archbishop Vigano.
"I will say sincerely that I must say this, to you," he said, when asked by a journalist about the letter, "and all of you who are interested: Read the document carefully and judge it for yourselves.
"I will not say one word on this. I think the statement speaks for itself."