Second division Osnabrück are the first German club to appeal sanctions over weeks-long fan protests against an external investor for the German Football League (DFL), and won't rule out taking the case to a civil court.
The German Football Federation (DFB) fined Osnabrück €20,000 ($21,700) for "unsportsmanlike conduct" by their fans who threw tennis balls and other objects onto the pitch at three home games as part of the protests, leading to interruptions.
The protests at many Bundesliga and second tier matches were one reason why the DFL eventually dropped its strategic partner plan.
The DFB has fined clubs over the incidents and said Osnabrück were now the first to appeal the DFB sports court ruling.
"If peaceful protests are not allowed to disrupt the expression of opinion, then a fundamental principle is being taken ad absurdum," managing director Michael Welling said in a club statement on Tuesday.
"This case also clearly shows once again in many facets that the DFB's legal and procedural regulations urgently need to be revised.
"We will therefore also consider going to the civil courts if the DFB's sports jurisdiction does not come to a different judgement than before after weighing up all the arguments."
Some clubs had suggested to the DFB to refrain from sanctions, and Osnabrück said they were in contact with other clubs in connection with their appeal.