The Vatican knew of a cover-up of child sex abuse by Roman Catholic priests in Pennsylvania through secret archives that bishops in the state shared with church leaders in Rome, the state’s attorney general Josh Shapiro said on Tuesday.

Though Catholic Bishops in Pennsylvania systematically denied the sexual abuse of thousands of children over a 70-year period, they secretly documented the cases and often sent information on them to the Vatican, Shapiro told two national news shows.

Shapiro first made the allegations against the Vatican during an Aug. 14 news conference to unveil a report on a two-year investigation into how Catholic clergymen in the state allegedly groomed and sexually abused children.

It was largely based on documents from the archives kept by the state’s six dioceses, he said.

‘There are specific examples where when the abuse occurred, the priests would go, the bishops would go and lie to parishioners, lie to law enforcement, lie to the public, but then document all the abuse in secret archives that they would share oftentimes with the Vatican,’ Shapiro told the CBS This Morning show.

‘There are specific examples where the Vatican knew of this abuse and they were involved in the cover-up,’ Shapiro said.

Shapiro did not comment on whether Pope Francis or his predecessors knew of the information.

The national review board of the US Conference of Catholic Bishops (USCCB), in a statement issued on Tuesday on social media, said the report showed the ‘culture of silence’ around sexual abuse of minors reached to the ‘highest level of the hierarchy’ of the Catholic Church, demanding change, specifically among bishops.

‘Holding bishops accountable will require an independent review into the actions of the bishop when an allegation comes to light,’ said the board, which was set up in 2002 to advise the USCCB on preventing sexual abuse of children in the Church.

Vatican press office director Greg Burke did not immediately respond to a request for comment on Shapiro’s allegations.

The attorney general said the Aug. 14 report was the most comprehensive on Catholic clergy sex abuse in American history, nearly two decades after an expose of widespread abuse and cover-up in Boston that rocked the Roman Catholic church.

In recent months, Pope Francis accepted a number of resignations from Chilean bishops in a sex abuse scandal that has rocked that country.