In their conclusions, the researchers write that there was evidence that some files were manipulated or destroyed, many cases were not brought to justice, and that sometimes abuse suspects - primarily priests - were simply moved to other dioceses without the congregations being informed about their past.
"The study is a course of action which we owe not only to the Church, but above all and foremost to those affected", Ackermann said.
Hickey says the discussion around abuse within the Catholic Church has exploded worldwide, but Newfoundland was ground zero. Every sixth case involved rape and at least 1,670 clergy were involved, both weeklies reported.
Most of the victims were boys, and more than half were aged 13 or younger.
All 27 dioceses in Germany participated in the research project.
The explosive report is hardly the first of its kind to shine a light on the rampant sexual abuse occurring in the Catholic Church. "We are dismayed and ashamed by it", said Bishop Stephan Ackermann of Trier on behalf of the bishops' conference.
"We know the extent of the sexual abuse that has been demonstrated by the study".
The study, commissioned by the German Bishops' Conference, was due to be presented officially on September 25, but several local media published key conclusions, including the damning finding that more than 3,600 children were sexually assaulted by priests in Germany over almost seven decades.
In 2010, the German church was roiled by a sex abuse scandal triggered by the head of a Jesuit school in Berlin who went public about decades-long sexual abuse of high school students by clergy. It established that there were 4,756 reported claims to Catholic Church authorities over child sexual abuse concerning 1,880 suspected abusers from 1980 to 2015. He said the Church had planned to provide counselling helplines for people affected by its contents.
The leaked study was published on the day Pope Francis summoned the presidents of the world's bishops' conferences to a summit on preventing clergy sex abuse and protecting children, responding to the greatest crisis of his papacy with the realisation that Vatican inaction on the growing scandal now threatens his legacy.
Last month, a grand jury in the US state of Pennsylvania released the findings of the largest-ever investigation of sex abuse into the Catholic Church in the United States, finding that 301 priests in the state had sexually abused minors over the past 70 years.
Pope Francis was caught up in the scandal last month, after a former Vatican diplomat accused him of ignoring allegations against a USA cardinal for five years.