Basilica di San Pietro in Vatican Photo: VCG

The Vatican on Tuesday denied a coverup over a US ex-cardinal accused of sexual abuse, admitting mistakes were made but saying Theodore McCarrick's crimes had for years been nothing but rumors.

A 450-page report on who knew what - and whether three consecutive popes overlooked McCarrick's abuse of at least one teenage boy and a number of male seminarians - accused senior US clergy of providing "inaccurate and incomplete information to the Holy See" about his behavior.

The influential former archbishop of Washington DC, who played a key role in raising funds for the Holy See from wealthy US donors, was stripped of his cardinal's title in 2018 and his priest's status in 2019.

Now 90, he was found guilty by the Vatican of the abuse of teenager in the 1970s as well as years of misconduct - such as inviting seminarians to his beach house where he made them share his bed.

He became the highest-ranking Church figure to be expelled in modern times.

The report, which comes with a graphic content warning and is based on documents as well as over 90 witness interviews, insists the first official allegation of pedophilia against McCarrick was not made until 2017 - at which point the Vatican reacted.

The Catholic Church has been rocked by a global pedophilia scandal, with victims coming forward from countries including Australia, Chile, and Germany, as well as the US.

The "often emotional" testimony from survivors in the McCarrick case revealed "sexual abuse or assault, unwanted sexual activity, intimate physical contact and the sharing of beds without physical touching," as well as detailed accounts of his abuse of power, the report said.

Survivors' groups have demanded to know how McCarrick, going by the nickname "Uncle Ted," was appointed to the prestigious Washington Post in late 2000 and created cardinal in 2001, despite anonymous letters from the early 1990s accusing him of the carnal abuse of his "nephews."

Former Pope John Paul II had been advised it would be "imprudent" to promote McCarrick, but the latter wrote to the pontiff in 2000 insisting he had never had sexual relations with any person, nor had ever abused another person.

His successor as pope, Benedict XVI, appears also to have been swayed by McCarrick swearing on his "oath as a bishop" that the allegations were false. The Vatican asked the cleric, however, to "maintain a low profile" - a request he ignored.

AFP