The target was Stefan Thumann, head of Bavarian company Donaustahl, which produces reconnaissance and kamikaze drones for Ukraine. German investigators are treating the case as suspected preparation for an assassination.
Serbian police stopped a truck on June 11, 2026, in which explosives were hidden, and according to investigators, the shipment was intended for Bavaria. This incident revealed a broader network of Russian intelligence operations targeting German defense companies, with the main target being Stefan Thumann, head of the Bavarian startup Donaustahl.
Donaustahl produces reconnaissance and kamikaze drones for Ukraine, and Thumann has publicly taken a strongly critical stance toward Moscow. "Russia does not want peace. It wants the destruction of the West," he wrote in one post, as reported by Euromaidan. According to security services, it was this public position that made him personally a target, rather than the company itself.
One of the hired operatives recorded Thumann's home and photographed his nameplate in December 2025. A foreign intelligence service then warned that Thumann was at high risk. Bavarian police arrested Serhii N., a former bricklayer from Kharkiv, but released him before analyzing his mobile devices.
After his escape to Spain, surveillance was reportedly continued by Romanian national Alla S. Both were arrested in March 2026-Serhii N. in Spain and Alla S. in the German state of North Rhine-Westphalia. In Serhii N.'s devices, investigators later found traces of communication with Russian intelligence officers and indications that he had been following Thumann's father.
Russia often recruits such "expendable" agents online, mainly among people in difficult financial or life situations. It pays them for surveillance, arson, and sabotage, and then disowns them. During 2026, Ukraine's SBU reported many cases where Ukrainians were recruited by Russia to carry out arson and sabotage within their own country.
Germany's Federal Office for the Protection of the Constitution (BfV), the domestic intelligence service, is treating the case as suspected preparation for an assassination. However, the federal investigating judge did not see sufficient evidence for that classification, so the arrest warrant only cites suspicion of espionage activity. Lawyers for both defendants declined to comment on the case.
The discovery of a truck full of explosives in Serbia suggests that another German defense industry company is a target of Russian intelligence services. In Bavaria, where the explosives were allegedly destined, Donaustahl, Quantum Systems, and Helsing have their headquarters.
The case fits into a series of earlier operations attributed to Russian services. In 2024, agents monitored Armin Papperger, head of the German defense company Rheinmetall. As early as 2019, a Georgian emigrant was killed in Berlin in an assassination linked to Russia's Federal Security Service (FSB). German authorities also view this case as part of a broader pattern of sabotage attributed to Russia across Europe in recent times.
Thumann is now under police protection but has not softened his messages to Moscow. "You will not break me," he said.
