A Cologne Catholic priest and other staff were discovered to have used church computers to view porn.
The Kรถlner Stadt-Anzeiger newspaper reported that around 1,000 attempts to view restricted sites were logged when the organisation ran a month of tests on its IT security systems.
The church disclosed that the tests, conducted between May and June last year, were not specifically to investigate the behaviour of staff or clergy.
According to the newspaper report, most of the suspicious activity in computer history concerned pornographic sites, with about 15 people involved in the act, including a senior priest.
The church informed BBC that the information was collated during a routine check of its IT securityโs ability to block access to sites that โpose a risk (violence, pornography, drugs, etc)โ.
The church also stated that using the church computers for watching pornography is strictly prohibited, and so is accessing material on drugs and violence. It said although it was โaware of the difficulty of the issueโ, it did not believe any crime was committed.
It added that there was โno evaluation of the specific content behind the URLsโ in questionโ but โno indications of criminally relevant conduct.โ
Also, a website for the Catholic Church in Germany, Katholisch.de, reported that public prosecutors were separately investigating a layman identified among the 15 on suspicion of possessing โcriminal contentโ.
The church informed BBC News that it was cooperating โfully with the state authoritiesโ and that the person concerned was โno longer activeโ in the organisation.
The vicar-general of Cologne, Guido Assmann, said the church was โvery awareโ of staff attempting to read blocked content on church computers, but he was โpleased that our security systems were effectiveโ.
โWe have a large number of dedicated and reliable employees, and it pains me greatly when the behaviour of individuals casts a shadow over their work,โ Mr Guido said.