The Archdiocese of Los Angeles was persuaded to shelter Father James Robinson, who during the 1970s and 1980s had raped several boys, after officials gave false information about his sexual history.
The Independent Inquiry into Child Sex Abuse concluded in a report published June 21 that the deception meant that Father Robinson "was able to remain in America and avoid prosecution for nearly 25 years."
It said Msgr. Daniel Leonard, former vicar general of the Archdiocese of Birmingham, England, where Father Robinson was trained, ordained and served as a priest, "deliberately misled the Archdiocese of Los Angeles about the nature of the allegations faced by Robinson."
The Irish-born Father Robinson was ordained in 1971, but the report said he was abusing boys before he entered seminary, during his formation and after he was ordained.
When one of his victims became an adult he went to the police on May 14, 1984 to complain about being abused and two days later Robinson fled to the United States.
In September that year Archbishop Maurice Couve de Murville of Birmingham wrote to the Los Angeles Archdiocese to approve the appointment of Robinson as a priest there.
The following month Msgr. Leonard admitted to his counterpart in Los Angeles that the reason for the move was because of an "unwholesome relationship" with a man Father Robinson had met 13 years earlier.
Within weeks the Los Angeles Archdiocese sought to return Father Robinson to England, said the report, but "Archbishop Couve de Murville personally wrote to the Archbishop of Los Angeles asking for Robinson to remain in California, stating 'how beneficial it would be for him if you could see your way to continuing the arrangement for a further period.'"
The report said it is unknown whether Archbishop Couve de Murville, who died in 2007, knew of the serious nature of the allegations made against Father Robinson.
Msgr. Leonard wrote to the Los Angeles Archdiocese, however, to assure officials there that because "Father Robinson has proved to be a completely open and uncomplicated priest since his ordination in 1971, I have no doubt about the accuracy of the account he has given you in maintaining that the alleged relationship with a man was an entirely false accusation."
The report said Msgr. Leonard might also have encouraged Father Robinson to flee to the U.S. when the allegations were first made to the police.
It said that having been informed of the complaint, Father Robinson "hastily arranged to go to America and Monsignor Leonard's correspondence with the Archdiocese of Los Angeles clearly assisted Robinson to remain in the USA."
"Monsignor Leonard's description of ... (the) abuse as an 'unwholesome relationship' sought to minimise the seriousness of what had happened," the report said, adding that the victim had been "sexually abused when he was still a child and Monsignor Leonard knew this."
The report said: "His description of the abuse was as inexcusable in 1985 as it would be today. It misled the Archdiocese of Los Angeles about Robinson's true character and enabled Robinson to remain in the USA and avoid prosecution for the next quarter of a century."
It noted that Msgr. Leonard died in 2003, adding, "We cannot say whether his motive for describing the abuse in this way was the protection of the archdiocese or simply a wish to move Robinson away from those whom he had abused and make Robinson another archdiocese's problem.
"Whatever the motive, Monsignor Leonard's actions failed to consider both the protection of children (including in the Californian parishes) and the impact that Robinson's departure would have on his victims and their attempts to bring Robinson to justice."
It was not until 1993 that Archbishop Couve de Murville notified church officials in Los Angeles that Father Robinson was a pedophile.
U.S. church authorities revoked his faculties immediately with the intention of returning sending him to England, but the priest disappeared and was found a decade later managing a trailer park in California by British Broadcasting Corp. journalists.
He was extradited to the U.K. where in 2010 he was sentenced to 21 years in jail for 21 sexual offenses involving four boys.
The report also criticized the actions of Cardinal Vincent Nichols of Westminster, who served as Archbishop of Birmingham from 2000-2009, for accusing the BBC of an "anti-Catholic bias" following the film broadcast about Father Robinson.
The Birmingham archdiocese is one of the worst afflicted by clerical sexual abuse in England and was nominated as a case study to represent the Catholic Church at the inquiry, which is investigating child abuse throughout a range of U.K. institutions.
A total of 130 allegations of sexual abuse against 78 people associated with the archdiocese went back some 90 years, the report said.