A court in the western city of Cologne has ruled that Germany's richest Catholic archdiocese doesn't have to reveal what it does with the billions it receives from taxpayers each year.

The investigative journalism group Correctiv had sued for the information, arguing that the Archdiocese of Cologne should be bound by laws granting media access to government information because much of its revenue comes from an income tax paid by Catholics in Germany.

But Cologne's administrative court ruled Thursday that the way the archdiocese invests its annual income of almost 3 billion euros ($3.4 billion) is protected by the church's constitutionally guaranteed autonomy.

The Archdiocese of Cologne welcomed the ruling, saying it already provides "full transparency and regular reports" on its long-term investments, which it said follow ethical principles.