The Ministry of Defence blamed an unnamed individual's improper use of a "non-secure data line" for the recent leak of a German army conversation about the Taurus weapon system to Russia.
The mistake was made by the participant who took part in the conversation from Singapore and had dialled in via a "non-secure data line" such as a mobile phone or via a wireless network, according to the interim result of an investigation presented on Tuesday by Defence Minister Boris Pistorius.
Pistorius ruled out the possibility that a Russian spy had taken part in the conversation without being noticed.
"Our communication systems were not compromised," he emphasized.
Pistorius said that preliminary disciplinary investigations had been initiated into all four participants in the conversation. However, he also emphasized that personnel consequences were "not currently on the agenda."
"[Unless something worse comes out] I will not sacrifice any of my best officers to Putin's games," emphasized Pistorius.
On Friday, Russia published a recorded conference of four senior officers, including German Air Force chief Ingo Gerhartz. In it, they discussed deployment scenarios for the German Taurus cruise missile if it were to be delivered to Ukraine.
Chancellor Olaf Scholz has ruled this out at the present time and justified his "no" by saying that Germany could then be drawn into the war. Taurus has a range of 500 kilometres and can therefore also hit targets in Moscow from Ukraine.
According to Pistorius, the conversation between the four officers took place via the Webex internet platform, which is used by the German Armed Forces, or Bundeswehr, in various protected versions for such conversations.
The conversation was able to be intercepted because a participant in Singapore had not adhered to the secure dialling-in procedure.
At the time of the conversation, the Singapore Air Show was taking place in the south-east Asian city state. The event was attended by many high-ranking European military officials.
"For Russian intelligence services, an event like this in this environment is understandably a real find," said Pistorius. The hotels used for the event had been bugged across the board.
The access to the Bundeswehr officers' Webex conference was a "chance hit as part of a broad, scattered approach," he said.
Pistorius emphasized that the Bundeswehr's communication systems must continue to be reviewed and improved upon on an ongoing basis. "We must continue to harden our systems," he said.
The "breadth of attacks" on the communication systems is increasing massively, he said, adding that he was not aware of any further cases of interception.
"But that doesn't rule out the possibility of another one."
