Germany's Federal Prosecutor's Office is convinced that the establishment of militarily organized units of a far-right group headed by German aristocrat Prince Heinrich XIII of Reuß was in part far advanced.
In two cases, the so-called homeland security companies could have become active independently, a representative of the authority said at the reading of the indictment.
Nine members of the group face charges of terrorism and high treason in a trial that started on Monday.
The suspected members of the Reich Citizens movement, known in German as Reichsbürger, a group that rejects the legitimacy of the modern German state, are accused of membership of a terrorist organization and "preparation of a treasonous undertaking."
One faces an additional charge of attempted murder.
Within one military company, those responsible for recruiting further personnel had already been named, the indictment read.
The prosecutor said that a variety of actions had also been registered to set up further homeland security companies. According to the indictment, the companies were supposed to carry out political "purges" in their area of responsibility after a potential takeover by the group.