Vatican City: A 2006 letter from a top Vatican official confirms that the Holy See received information in 2000 about the sexual misconduct of now-resigned US cardinal, lending credibility to bombshell accusations of a cover-up at the highest echelons of the Roman Catholic Church.

Catholic News Service, the news agency of the US bishops' conference, published the letter Friday from then-Archbishop Leonardo Sandri to the Rev. Boniface Ramsay, a New York priest who made the initial allegation.

Ramsay informed the Vatican in a November 2000 letter about then Cardinal Theodore McCarrick's misconduct with seminarians from Seton Hall University's Immaculate Conception Seminary. Ramsay, who in 2000 was on the faculty at the seminary, has said he sent the letter at the request of the then-Vatican ambassador because he had heard so many complaints from seminarians that McCarrick would invite them to his beach house and into his bed.

Sandri, now a top-ranked Vatican cardinal who was the No. 3 in the Vatican's secretariat of state at the time, wrote Ramsay on October 11, 2006, seeking his recommendation for a former seminarian for a Vatican job.

In it, he referred to Ramsay's 2000 letter, saying: "I ask with particular reference to the serious matters involving some of the students of the Immaculate Conception Seminary, which in November 2000 you were good enough to bring confidentially to the attention of the then-Apostolic Nuncio in the United States, the late Archbishop Gabriel Montalvo."

Archbishop Carlo Maria Vigano, at the centre of a storm rocking Pope Francis' papacy, cited Ramsay's 2000 letter in his own expose of a cover-up about the McCarrick affair. He named Sandri among a long list of Vatican officials who knew about McCarrick's penchant for seminarians. Vigano also accused Francis of knowing in 2013 of McCarrick's misconduct but of rehabilitating him from sanctions purportedly imposed by Pope Benedict XVI.

Sandri's letter is significant because it corroborates Ramsay's story as well as Vigano's claims. It shows the Vatican knew about allegations against McCarrick in 2000, a year before St. John Paul II made him a cardinal. And it further implicates Benedict's papacy for failing to take action against McCarrick for years even as more allegations against him arrived.

Vigano says Benedict eventually imposed some form of sanction on McCarrick in 2009 or 2010, nearly a decade after Ramsay's letter arrived. The fact that Sandri cited it so readily suggests it wasn't lost in a pile of unread mail somewhere but was relevant even for a simple job reference.

Significantly, Sandri appeared more concerned about the sexual purity of the seminarian-candidate than that McCarrick might have sexually abused or harassed him, or abused his power over him.

McCarrick resigned as a cardinal in July after a US church investigation determined an accusation that he groped a teenage altar boy in the 1970s was credible. Since then several seminarians have come forward to say he routinely bedded them, or harassed them when they refused.

His lawyer has said the accusations are serious and that McCarrick looks forward to invoking his right to due process at the right time.