(Bloomberg) -- German police have detained a second man suspected of passing classified material from the BND foreign intelligence service to Russia, in a case Vice Chancellor Robert Habeck has called “particularly troubling.”

In an emailed statement Thursday, the federal prosecutor named the man as Arthur E. and said he had been taken into custody at Munich Airport after arriving from the US.

A German citizen and not a government employee, the man is accused of receiving information from a senior BND analyst and traveling to Russia to deliver it to an intelligence service there, according to the statement. The analyst was detained last month.  

The BND case is the latest instance of apparent Russian spying in Germany, a phenomenon that strained relations between Berlin and Moscow even before Russia’s full-scale invasion of Ukraine 11 months ago.

German officials have also accused the Kremlin of mounting cyber attacks within the country and seeking to influence the 2021 national election.

Germany’s Federal Office for Information Security said on Thursday that attempted hacks are currently underway against targets including airport websites and the financial sector. “Websites of the federal and state administration are also under attack. However, these attacks have so far been largely averted and have not had any serious impact,” it said in a statement. 

Read More: Germany Warns Kaspersky Software Risks Being Exploited by Russia

Russia was already suspected of engaging in extrajudicial activity in Germany. In August 2019, a former Chechen military commander was gunned down in broad daylight in a central Berlin park, allegedly at Moscow’s behest.

The investigation into the senior analyst, named as Carsten L., is being conducted in close cooperation with the BND and the US Federal Bureau of Investigation, the prosecutor said Thursday.

German officials are worried that he may have given Russia information that was shared by the US National Security Agency and Britain’s GCHQ, Focus magazine reported last month, citing unidentified security sources in Berlin.

(Adds statement on hacker attacks in sixth paragraph.)

©2023 Bloomberg L.P.