A former ambassador to the Vatican has accused Pope Francis of ignoring sexual abuse claims against prominent US cardinal Theodore McCarrick, who was forced to resign last month.
Archbishop Carlo Maria Vigano said that he had told Francis, who is currently visiting Ireland, of the allegations in 2013, but that the pontiff instead lifted sanctions imposed on McCarrick by predecessor Pope Benedict.
Vigano's eleven-page letter was published simultaneously on Saturday in several conservative Catholic publications in the US.
The Pope on Saturday said he shared in the "pain and shame" of the church's failure to deal with historic allegations of clerical abuse, and the latest claims are likely to intensify calls for action.
The Vatican said it had no comment to make on the allegations.
Bishop Vigano, 77, who was a papal nuncio in Washington between 2011 and 2016, said that Benedict XVI imposed canonical sanctions against Cardinal McCarrick in the late 2000s.
McCarrick was forced to leave the seminary where he lived, avoid all public contact and live a life of penance after former Vatican ambassadors in Washington, now dead, reported him for "gravely immoral" behavior with seminarians and priests.
Vigano claims Pope Francis asked him about McCarrick when he took office in June 2013, but that Francis ignored his warnings, and instead made him a "trusted counselor."
"He (Pope Francis) knew from at least June 23, 2013 that McCarrick was a serial predator," wrote Vigano," adding "he knew that he was a corrupt man, he covered for him to the bitter end."
The former nuncio wrote that Francis was "abdicating the mandate which Christ gave to Peter to confirm the brethren," and urged him to "acknowledge his mistakes".
The pope was on Sunday due to preach in front of around 500,000 people in Dublin at the end of a two-day visit to Ireland.