Lower Saxony's Greens have become the target of a fake campaign.
According to a party spokeswoman, fake party posters were put up in at least four cities - Hanover, Osnabrück, Göttingen and Lüneburg - and the homepage of the Greens' regional association was copied and a false press release added, which was also sent by e-mail.
The Greens already filed criminal charges for the action on Tuesday.
Among other things, Lower Saxony's deputy prime minister and Volkswagen supervisory board member Julia Willie Hamburg can be seen on the posters with the slogan "VW stands for traffic change".
Another poster shows Federal Economics Minister Robert Habeck with a tip against Federal Transport Minister Volker Wissing (FDP).
"These are not our contents," emphasized the Greens spokeswoman Heike Köhn on Thursday.
"It is still completely unclear who is behind it," said Köhn.
"We're on to it." According to the party, the originators of the campaign are disrupting the political debate by posing with their messages as the Greens and as elected officials.