A second German man is now being investigated as a potential U.S. informant, German paper Süddeutsche Zeitung reported on Wednesday.
According to the report, officials from Germany's Federal Criminal Police Agency (BKA) and the public prosecutor's office have searched the Berlin-area "residential and office premises of an employee of the Ministry of Defense, said to have been spying for a U.S. intelligence in Germany."
The prosecutor's office issued a statement early Wednesday saying that the search is ongoing, though no further information could be issued at this time.
The report comes a week after German authorities arrested a first alleged "double agent," who was an employee of Germany's federal intelligence service, known as the BND, but was paid by U.S. officials to provide information on the parliamentary investigation into NSA surveillance of German citizens and officials.
According to Süddeutsche Zeitung, the two cases are independent of each other. However, both allegations come in the wake of documents leaked by NSA whistleblower Edward Snowden that revealed that one of the top U.S. allies, German Chancellor Angela Merkel, was among the foreign leaders being targeted by the widespread surveillance.
As the New York Times notes, these incidents "she[d] light on the tensions that arise from the colliding cultures of spycraft and statecraft — one driven by the need to vacuum as much secret material as possible; the other giving primacy to diplomatic objectives."