The suspect worked as a professional soldier at the Federal Office of Bundeswehr Equipment, Information Technology and In-Service Support (BAAINBw). The institute is responsible for equipping Germany's armed forces, the Bundeswehr. It also develops, tests and procures military technology.
German officials said the country's support for Kyiv has increasingly made it the target of Russian spying since Russia launched its full-scale invasion of Ukraine.
Earlier this month, Moscow published a leaked wiretap in which Bundeswehr officials were heard discussing potential arms deliveries to Ukraine, reports DW.
What is the suspect accused of?
The man is accused of going to Russia's consulate in Bonn and its embassy in Berlin to offer his cooperation multiple times since May 2023. Prosecutors said he offered the help "on his own initiative."
The German citizen has been in custody since August.
Prosecutors said he handed over information obtained during the course of his work at the BAAINBw.
He was arrested in Koblenz in the southwestern state of Rhineland-Palatinate and his home and workplace were searched by police.
The security division of the Düsseldorf Higher Regional Court must now decide whether the case will go to trial.