Speaking out on the most important clergy sexual abuse issue in the United States, Boston Cardinal Sean O’Malley said the Vatican must do something quickly about Bishop Robert Finn, the Kansas City prelate convicted of failing to report child abuse by one of his priests.

Finn, convicted two years ago, was sentenced to two years of probation for waiting six months before telling police that diocesan officials had found pornographic images of young girls on the computer of the Rev. Shawn Ratigan, one of his parish priests.

Ratigan pleaded guilty to child pornography charges and was sentenced to 50 years in federal prison; Finn has remained the bishop of the diocese.

Speaking to CBS News, O’Malley agreed that under the Catholic Church’s zero-tolerance policy, he wouldn’t let Finn even teach Sunday school in Boston, let alone head a diocese.

“It’s a question the Holy See needs to address urgently …. There’s a recognition of that from Pope Francis,” O’Malley told 60 Minutes reporter Norah O’Donnell in an interview scheduled to air Sunday.

In another bold statement during the interview, O’Malley called a doctrinal investigation of American nuns started by Pope Benedict XVI and continued by Francis “a disaster.”

O’Malley is one of eight personal advisors to Pope Francis, and earlier this year he was tapped to lead the Vatican’s new sexual abuse commission aimed at strengthening rules to protect children.

(Related: Globe interview with O’Malley in February)

Victims-rights groups have consistently criticized the Church for failing to hold bishops accountable for protecting pedophile priests, pointing to Finn as a prime example. The fact that Finn has remained in power after a criminal conviction has made him a lightning rod for this perceived lack of accountability.

However, in September, the Vatican confirmed that Finn’s leadership was under investigation by Church authorities, a possible prelude to his removal. Archbishop Terrence Prendergast of Ottawa visited the Diocese of Kansas City-St. Joseph and spoke with several people, asking if they considered Finn fit for leadership.

If the Vatican acts against Finn, it could be the most significant step Pope Francis may ever take with regard to the Church’s child sexual abuse scandals; for the first time, a bishop would be held accountable not for the crime of sexual abuse, but for a cover-up.

Finn is not the only American bishop under scrutiny. Archbishop John Nienstedt of St. Paul-Minneapolis has faced calls for his resignation over his handling of priests who sexually abused children.

Earlier this year, O’Malley said the commission he leads, which includes a lay survivor of sex abuse, would seek widespread accountability. “Our concern about accountability is accountability for everyone in the Church, regardless of what their status is,” he said.

The pope made similar promises in July after a private Mass with victims of clergy sexual abuse at the Vatican. “I beg your forgiveness … for the sins of omission on the part of Church leaders who did not respond adequately to reports of abuse made by family members, as well as by abuse victims themselves,” he said. “This led to even greater suffering on the part of those who were abused, and it endangered other minors who were at risk.”

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The Vatican’s investigation into American nuns is focused on the Leadership Conference of Women Religious (LCWR), a group of Catholic sisters that represents about 80 percent of the 50,000 nuns in the US. It was established in 1956 with Rome’s backing. But in recent years, as American bishops became more conservative, they grew increasingly critical of the liberal tilt of the various congregations of sisters under the LCWR umbrella.

Behind-the-scenes efforts to rein in the sisters went public in April 2012, when the Vatican revealed that it had been investigating the LCWR and charged that the American sisters were straying too far from traditional doctrines in the theological speculations of some members.

The Vatican’s doctrinal watchdog, German Cardinal Gerhard Müller, also said the sisters were focusing too much on social justice issues, such as caring for the poor and advocating for immigrants, and were too active in promoting health care reform. It said the LCWR members should spend more time advancing Church teachings on sexuality and abortion.

The Vatican announced that it intended to overhaul the LCWR and Pope Benedict XVI appointed a trio of US churchmen, led by Seattle Archbishop J. Peter Sartain, to oversee the process and have final approval on the LCWR’s major decisions.

The nuns, who were surprised by the report, rejected the Vatican’s charges. They said taking care of society’s poor and vulnerable people is central to their historic mission, and the theological ideas of some in their ranks were efforts to articulate that mission in today’s Church and today’s world.

Crux associate editor John L. Allen Jr. contributed. Material from the Associated Press and Religion News Service was used in this report.