DNY59/iStockBy PETE MADDEN, ABC News

(NEW YORK) -- New York Attorney General Letitia James filed a lawsuit on Monday against the Catholic Diocese of Buffalo and its former leaders Bishop Richard Malone and Bishop Edward Grosz, alleging that they engaged in a years-long cover-up of accusations of sexual abuse of minors by local priests.

Over a two-year investigation, James' office identified more than two dozen diocesan priests who were credibly accused of abuse but were not, according to the complaint, immediately referred to the Vatican for possible removal from the clergy in accordance with the church's established policies and procedures.

"For years, the Diocese of Buffalo and its leadership failed to protect children from sexual abuse," said Attorney General James in a statement. "Instead, they chose to protect the very priests who were credibly accused of these atrocious acts."

The lawsuit also seeks to bar Bishops Malone and Grosz from future service as directors or officers of any charitable organization subject to New York law, citing their alleged violations of their fiduciary duties to the diocese.

Diocese of Buffalo spokesperson Gregory Tucker told ABC News they will be "reviewing" the suit and "weighing the Diocese's response."

"In the meantime, we wish to reiterate that there is zero tolerance for sexual abuse of a minor or of sexual harassment of an adult in the Diocese of Buffalo by any member of the clergy, employee or volunteer," Tucker said in a statement. "The Diocese has put in place rigorous policies and protocols governing required behavior as well as a code of conduct which all clergy are expected to abide by. Moreover, the Diocese has committed to full cooperation with all civil authorities in both the reporting and investigation of alleged crimes and complaints."

The Diocese of Buffalo is currently seeking bankruptcy protection following a flood of lawsuits under New York's Child Victims Act, which created a look-back window allowing allegations of sexual abuse that would otherwise be barred by the statute of limitation to be filed.

Bishop Malone resigned in December 2019 in the wake of a Vatican review of the diocese prompted by widespread criticism of his handling of allegations of sexual abuse and misconduct by local clergy members. Bishop Grosz resigned in March 2020 upon reaching mandatory retirement age for bishops.

The Diocese of Buffalo had been in a state of crisis since 2018, when Siobhan O'Connor, Malone's former personal secretary, leaked internal church documents to investigative reporter Charlie Specht from ABC's local station WKBW-TV, sparking months of reporting about whether there had been efforts to conceal the extent of the sexual abuse problem from the public.

In an interview with ABC News that aired as a special edition of "Nightline," Malone admitted that he had made some mistakes but defended his leadership.

"I feel that in the almost 20 years I have been a bishop, I've tried hard to be a good shepherd," Malone told ABC News, arguing that he had "inherited a decades old horrific problem of abuse."

But in Monday's 216-page complaint, James claimed Bishops Malone and Grosz "sheltered accused priests" and "wasted charitable assets" in supporting them.

"In numerous cases," the complaint alleges, "Malone and Grosz failed to properly examine or address individual complaints and disregarded the risks created by their decisions to avoid procedures required under Church law and the Diocesan Corporation's policies and procedures."

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