WASHINGTON, Aug. 14 (Xinhua) -- More than 300 "predator priests" from six Catholic dioceses across eastern U.S. state Pennsylvania have been accused of sexually abusing over 1,000 child victims, according to a new grand jury report released Tuesday.

The report, issued by the Pennsylvania Supreme Court, also details a "systematic coverup by senior church officials in Pennsylvania and at the Vatican" over more than six decades, State Attorney General Josh Shapiro said at a news conference on Tuesday.

Shapiro said that over 1,000 children victims were identifiable from the church's own records, and the grand jury believes there are more.

"We believe that the real number - of children whose records were lost, or who were afraid ever to come forward - is in the thousands." reads the grand jury report introduction.

Church leaders in these Catholic dioceses were more interested in safeguarding the church and the "predator priests" than helping their victims, the redacted report says.

"The main thing was not to help children, but to avoid scandal," the report says. "Priests were raping little boys and girls and the men of God who were responsible for them not only did nothing: They hid it all."

One of these "predator priests" pleaded guilty last month to charges that he sexually abused a 10-year-old boy more than 20 years ago. Another has been charged with felony child sex crimes, according to local media reports.

However, some of the accused have died, and statute of limitations laws prevent many others from facing criminal charges, said the media reports here.

The investigation is the most comprehensive yet on Catholic Church sex abuse in the United States, said the reports.