Cooperation between the Lower Saxony Institute for Criminology (KFN) and the German Bishops' Conference ended due to unacceptable interference by the Church, KFN director Christian Pfeiffer told broadcaster Deutschlandfunk on Wednesday.
He said the institute had already been told by the Church that its services would no longer be needed after the KFN refused to comply. This will be confirmed in a letter from the Association of German Dioceses (VDD) to the KFN in the coming days, the Süddeutsche Zeitung reported on Wednesday.
The project had been scuppered by the "censorship and control requests of the Church," Pfeiffer told the paper.
The cooperation had been contractually agreed in July 2011, and was to be the most thorough investigation of its kind in the world, the KFN said. The complete files of all of Germany's dioceses - some dating as far back as World War II - were to be scrutinized for evidence of child abuse.
But last year, the Church demanded changes to the contract following complaints from priests and some bishops. These alterations included giving the Church the power to veto the publication of results and the appointment of new researchers.
Pfeiffer also said there were indications that the Church had destroyed incriminating files in several dioceses, a claim denied by VDD Chairman Hans Langendörfer. "I have no evidence that abuse files were destroyed," he said.
A spokesman for the archdiocese of Munich and Freising rejected Pfeiffer's claims, saying that there was absolutely no grounds for talk of "censorship requests."
Instead, the discussion had been about "how the unconditional will for clarification in the interests of the victims could be brought together with the necessary duty of care towards church workers." He added that the main issue was data protection.
Revelations in 2010 of child abuse at the Catholic Canisius School in Berlin unleashed a wave of allegations against the Church in Germany.