Two Roman Catholic bishops were involved in covering up extensive sexual child abuse in their central Pennsylvania diocese over four decades, according to a grand jury report made public Tuesday.

The 147-page report reveals that the two bishops helped hide the abuse by moving offending priests to different parishes, mandating counseling and paying off victims.

Bishops James Hogan and Joseph Adamec led the Altoona-Johnstown Diocese for consecutive terms, Hogan from 1966 to 1986 and Adamec until 2011. During those years, hundreds of children were sexually abused by more than 50 religious leaders in the eight-county diocese.

"These predators desecrated a sacred trust and preyed upon their victims in the very places where they should have felt most safe," Pennsylvania Attorney General Kathleen Kane, who was instrumental in the investigation, said in a statement. "Just as troubling is the cover-up perpetrated by clergy leaders that allowed this abuse to continue for decades."

No criminal charges have been filed as some abusers have died, it is now past the statute of limitations, and victims don't want to relive the trauma by testifying, according to Kane.

Hogan died in 2005 and Adamec refused to testify before the grand jury in November, but the new report arises largely from evidence found in secret diocese documents that officials collected after issuing a search warrant.

The grand jury report contends Adamec had gone so far as to threaten victims with excommunication and even created a "pay-out chart" detailing how much money to give victims to keep quiet based on the crime committed. The payments ranged from $10,000 to $175,000 depending on the specific sexual act that was forced upon the child victim.

Hogan, according to the report, transferred offending priests among parishes and intervened in law enforcement efforts to prosecute priests.

"The police and civil authorities would often defer to the diocese" in cases of priests being accused of sexual abuse, the report said.

Altoona's former police chief Peter Starr even testified that diocese officials wielded political power and that he suspects a monsignor was behind his own appointment as chief of police.

This report arises as the latest in a series of investigations into Catholic leaders' involvement in sexual abuse of children. These investigations into church sexual abuse scandals began in 2002 when The Boston Globe reported that bishops in the Boston Archdiocese were transferring abusers to different parishes rather than removing them from service. That reporting was the subject of Spotlight, a film that won the Academy Award for best picture on Sunday.

The Pennsylvania report also comes on the heels of testimony by Australian Cardinal George Pell, one of Pope Francis' top advisers, regarding the Vatican's current efforts to address sexual abuse issues and how aware he was of sexual abuse at the hands of Australian priests in the 1970s.

In Sunday's hearing, Pell said he may have been too trusting. "I must say in those days, if a priest denied such activity, I was very strongly inclined to accept the denial," he said.

This report contains material from the Associated Press.