The pope's hand-picked replacement to oversee abuse cases at the Vatican did nothing to restrict a California priest after learning in 1995 that the priest had molested a 13-year-old boy a decade earlier.
Cardinal William Levada, then Archbishop of San Francisco, said in a 2005 deposition obtained by the Associated Press that he did nothing and didn't contact police because he trusted the Rev Milton Walsh would not reoffend and his predecessor handled the case adequately.
There were no known allegations of later abuse by the priest and a Vatican attorney says Dr Levada acted appropriately under standards of the time.
When Dr Levada learned of the abuse, Walsh had been pastor for six years at St Mary's Cathedral in San Francisco. He remained there for two more years and was removed from active ministry in 2002, when US bishops passed a "zero tolerance" policy on sex abuse.
Dr Levada is now the highest-ranking American at the Vatican and head of the office that defrocks paedophile priests. Cardinal Ratzinger held the post before becoming Pope.
The Vatican's lawyer, Jeffrey Lena, said: "One thing the law teaches: it is fundamentally unfair to apply standards of conduct retroactively."
Dr Levada's critics call it an example of his disregard for abused children. "He never reached out in this clear-cut case. That's typical of Levada and perhaps why he's in the position he's in," said Diane Josephs, the attorney for Walsh's victim, Jay Seaman.