BERLIN — A criminal investigation into an artist who built a partial replica of Germany’s national Holocaust memorial next to the home of a far-right politician has been formally closed, more than 16 months after it began but less than a week after its existence became public.
But reverberations from the inquiry into the artist, Philipp Ruch, and his collective, the Center for Political Beauty, have continued to spread. On Thursday, a letter was released from more than 100 prominent German cultural figures, academics and politicians expressing “disbelief” at the investigation, which employed a legal provision more often used to monitor gangs, extremist groups and terrorist cells.
The letter demands an apology and an explanation from those who undertook the investigation, and calls on them to disclose any political links: Martin Zschächner, an attorney for the state of Thuringia who was in charge of the case, has been accused by the left-wing politician who uncovered the inquiry of being soft on far-right offenders.
The outcry has come after a public discussion about right-wing activists in positions of public authority, and after several publicized cases of extremists among police and army officers.
The weekly newspaper Die Zeit has reported that during the course of the investigation, Mr. Zschächner donated 30 euros, about $34, to Alternative for Germany, the far-right party represented in Thuringia’s State Assembly by Björn Höcke, the target of Mr. Ruch’s artwork.
On Monday, when the investigation was formally closed, Mr. Zschächner was taken off the portfolio of state security and moved to less sensitive duties.
Mr. Zschächner has not responded to Die Zeit’s report, and could not be reached for comment on Thursday.
In a phone interview with The New York Times last week, he said the investigation was not political, but had been prompted by the collective’s own statements about another part of the work: a fake spy room, open to the public, in which Mr. Ruch and his colleagues pretended to monitor Mr. Höcke’s home with old electronic equipment.
“On their internet page they said they wanted to spy on him, so the question is whether that happened or was planned,” Mr. Zschächner said.
Mr. Höcke, who inspired Mr. Ruch’s artwork by denouncing the Holocaust memorial in Berlin as a “monument of shame,” is currently one of only seven Alternative for Germany representatives in Thuringia’s 91-seat state legislature. But the party is poised to make significant advances in the state election this coming October.
In an interview, Dieter Lauinger, Thuringia’s minister of justice — a Green Party politician serving as part of a three-party, left coalition — insisted that the investigation itself was inactive and had never made use of the powerful tools legally available to it, such as wiretaps and the employment of informants.
While he was firm that the investigators were just following normal procedure in opening the case, he did say the length of time it had remained open was problematic, especially because other judicial investigations over the artwork were soon dropped.
“From very early on, I’ve criticized the length of the investigation,” he said.
But at least one of the letter’s writers considers the matter to be more sinister than that.
“This is something we otherwise only see in countries like Turkey or Russia — autocratic countries where art is criminalized, where artists, journalists and scientists who do not conform to the government are branded as terrorists and traitors,” said Shermin Langhoff, the artistic director of the Maxim Gorki Theater in Berlin and one of the authors of the letter.
Ms. Langhoff, who organized and helped write the letter, and whose theater exhibited Mr. Ruch’s artwork in 2017, argued that the investigation had been launched for entirely political reasons.
The letter’s 145 signatories include some of the country’s most well-known musicians, actors, theater and film directors, academics, television hosts, writers and progressive politicians, from Herbert Grönemeyer, one of the country’s most famous singers, to Cem Özdemir, a popular lawmaker and former leader of the Green Party.
“Our concern is really the intimidation of art and we think as artists and culture makers we have to say something,” said Ms. Langhoff in an interview. “That’s why I took the initiative.”