BERLIN (AFP) - More than 3,600 children were sexually assaulted by Catholic priests in Germany over nearly seven decades, local media reported on Wednesday (Sept 12), citing a study commissioned by the German Bishops Conference.

The damning report, which Cardinal Reinhard Marx is to present officially on Sept 25, deals another blow to the Church after clerical child abuse has been uncovered worldwide.

According to the study, 1,670 clergymen in Germany committed some form of sexual attack against 3,677 minors between 1946 and 2014, Spiegel Online reported. Most of the victims were boys.

More than half were 13 years' old or younger at the time of the abuse, the study concluded after examining 38,000 documents from 27 German dioceses.

The study also noted that some records had been "destroyed or manipulated", warning therefore that the scale of the abuse may be even greater.

Predator priests were often transferred to another location, with information on their criminal history not provided to the new site.

Only one in three (566 out of 1,670 accused) were subject to disciplinary hearings by the Church, and most got away with minimal punishment, said Die Zeit weekly, also citing the report.

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Of these, 154 cases ended with no penalty, while 103 closed with a warning.

Only 38 per cent of the accused were prosecuted by civil courts on complaints lodged by victims themselves or their families.

Over the last decade, several German Catholic institutions have revealed cases of child sexual abuse, including an elite Jesuit school in Berlin which admitted to systematic sexual abuse of pupils by two priests in the 1970s and 1980s.

Last year, a world-famous Catholic choir school in Germany, the Regensburger Domspatzen school, revealed that more than 500 boys there suffered sexual or physical abuse in what victims have likened to "prison, hell or a concentration camp".