Five people have been charged with a terrorist plot to kidnap a German minister and spark "civil war-like conditions" to overthrow the government.
The suspects hoped to bring down the state and replace it with an authoritarian regime modelled on the former German Empire, prosecutors said.
Their alleged plot would have involved abducting Health Minister Karl Lauterbach, possibly killing his bodyguards and seizing power in the ensuing chaos.
It comes weeks after raids across Germany that uncovered a separate alleged coup plot.
The new charges are linked to the same fringe ideology that rejects the legitimacy of Germany's post-war democracy.
Mr Lauterbach's support for tough restrictions during the pandemic has made him a hate figure to some right-wing groups.
He said on Monday he was grateful to investigators for protecting him and arresting the suspects.
His abduction was part of a three-stage plan in which the plotters would have caused power cuts, assembled a phoney parliament, deposed the government and reinstated an 1871 constitution, it is alleged.
The four men and one woman "formed a group with the aim of triggering civil war-like conditions in Germany, with the use of violence and, at minimum, the acceptance of fatalities", a statement from prosecutors said.
It said they believed that "the German Reich continues to exist ... therefore, an authoritarian form of government should be established, modelled on the former German Empire".
Two of the suspects, named only as Thomas O and Sven B under German privacy laws, allegedly planned to obtain weapons and explosives, notably from the Balkans. Sven B was said to be the leader of the group's "military branch".
Thomas O was arrested after acquiring two AK-47s, four Glock handguns and a supply of ammunition, prosecutors said. He allegedly gathered maps to help him plan for knocking out power.
All five suspects are accused of high treason and forming a terrorist cell. Some are suspected of preparing acts of violence and breaking terrorist financing and weapon laws. All have been in custody since last year.
Ministers were already drafting tougher weapon laws after last month's raids and an unrelated outbreak of violence on December 31.
The December coup plot allegedly involved a minor German aristocrat and a former MP from the far-right Alternative for Germany party.
The Reichsbuerger [Citizens of the Reich] movement linked to the plot was also connected to anti-lockdown protests in 2020 and 2021, in which Mr Lauterbach was sometimes pilloried.
It has no clear leadership or firm ideology, but claims allegiance to a German Reich that existed from 1871 until its dissolution by the wartime allies in 1945.