German investigators on Thursday raided the country's finance and justice ministries as part of a money-laundering probe.
The ministries were suspected of obstructing justice by failing to hand over evidence amounting to "millions of euros" of laundered money, prosecutors said.
The case is focused on employees of a Cologne-based unit of Germany’s customs service that fights money laundering.
Since February last year, prosecutors have been looking into allegations that the Financial Intelligence Unit (FIU) didn’t forward indications of possible money laundering from banks to police and courts.
"We don’t know at present why the data was not passed on," prosecutor Alexander Retemeyer told state television.
"It might just have been because of overwork but it could also have some other background, which we now want to try to find out."
No suspects have yet been identified or arrested in the investigation.
Previously-seized documents have shown that there was "extensive communication" between the FIU and the two ministries, prosecutors in the western city of Osnabrueck said.
The ministries have said the suspicion of wrongdoing was not directed against their own employees and added that they were supporting the investigation.
The searches on Thursday come just over two weeks ahead of Germany's parliamentary election, where Finance Minister Olaf Scholz is running for chancellor.
German justice minister Christine Lambrecht is also a member of Scholz's centre-left Social Democrats, who are currently leading polls.