Not the OP, but this was a theme in the European Parliament in 2022 [1][2] and it was the object of a document that Greenpeace made [3] showing how pervasive the Russian lobby was over climate policies.

I personally do not believe that Russia does it in Germany via the Green Party but more so over other parties, such as AfD and BSW.

[1] - https://www.europarl.europa.eu/doceo/document/P-9-2022-00127....

[2] - https://www.europarl.europa.eu/doceo/document/P-9-2022-00127....

[3] - https://www.greenpeace.de/publikationen/20220517-greenpeace-....