Pope Francis on Thursday promised Chilean Catholics scarred by a culture of clergy sexual abuse that "never again" would the Church ignore them or the coverup of abuse in their country, where a widespread scandal has devastated its credibility.

The pope issued the comments in a letter to all Chilean Catholics as the Vatican announced that Francis was sending his two top sexual abuse investigators back to the country to gather more information about the crisis there.

The Vatican's most experienced sexual abuse investigator, Archbishop Charles Scicluna of Malta, and Father Jordi Bertomeu, a Spaniard, had visited Chile earlier this year.