Conspiracy theorists could have a field day with this one: The right-wing extremist National Socialist Underground (NSU) could have been a product of the German intelligence services.

Reporting by a team of journalists working with Stefan Aust, editor-in-chief at the "Welt" newspaper, has revealed that two of the three alleged right-wing terrorists worked for a demolition company in Zwickau after supposedly having gone underground. It's without a doubt that from 2000 to 2002 Uwe Mundlos worked under a false name at the construction service company owned by neo-Nazi Ralf Marschner, according to the authors. As an informant, he was delivering information about the right-wing scene to the intelligence services.

During the same period, the first five of ten racially motivated murders took place, for which the NSU claimed responsibility in a video. On the day of its revelation, November 4, 2011, the bodies of Uwe Mundlos and his accomplice, Uwe Böhnhardt, were discovered in a burned-out mobile home. The duo allegedly committed suicide in order to avoid their capture following an unsuccessful bank robbery.

Government authorities quiet for 'the good of the state'

The third member of the group, Beate Zschäpe, now stands before a court in Munich, the main defendant in the so-called NSU trial. She may possibly have worked for the same informant as Mundlos. But her story was being deduced from circumstantial evidence, which may or may not prove to be valid, Aust told the MDR, a German broadcaster, on Thursday.

He was speaking after the airing of "The NSU Complex," a television mini-series, in which the connection between the informant and Uwe Mundlos is spoken of for the first time.

Uwe Böhnhardt and Uwe Mundlos died in a fire to avoid capture

As in every other case, the truth behind this is not something that can be definitively confirmed. Policies for the protection of informants prevent that. When asked about it, Interior Minister Thomas de Maizière (CDU) gave the "Welt" a standardized answer: Regarding informants, the government "for reasons of national security, cannot make disclosures."

The Federal Office for the Protection of the Constitution, Germany's domestic intelligence service, did not have any clue that Mundlos worked for Marschner, according to President Hans-Georg Maaßen.

The mysterious cases of 'Andreas T', 'Piatto' and 'Corelli'

The latest revelations renew suspicions that government authorities know more about the NSU than they will admit. In the numerous parliamentary inquiries as well as during the NSU trial, every attempt at clarification runs aground when it comes to the intelligence services. The most sensational case is that of Andreas T., an informant leader who was sitting in the Internet cafe in Kassel on April 6, 2006, when the owner, Halit Yozgat, was shot. He lied, pretending that he didn't even know of the place. Police investigations on the suspicion of murder were shelved. Further insights may very well exist in the files of Hesse's intelligence service, but they remain under lock and key.

Likewise, informant "Piatto" remains a mystery in many respects, his motivation opaque as information is being withheld. The violent convicted criminal had offered his services to the intelligence agency while he was in prison. He is said to have known the whereabouts of the NSU trio after their disappearance in the late 1990s.

Or take "Corelli," the best contact within the right-wing extremist scene in Baden-Wurttemberg: On April 7, 2014, shortly before a planned police interrogation, he died. The authorities had hoped to get new information about the NSU murder of policewoman Michèle Kiesewetter in Heilbronn. The official cause of the 39-year-old's death: diabetes.

Beate Zschäpe is on trial in Munich

Informant Tino Brandt rhapsodizes about the good old days

Tino Brandt is a key figure for connections between the NSU and the intelligence services who cannot be overlooked. The Thuringian Nazi was unmasked as an informant at the turn of the century and was branded a traitor in the scene. In the meantime, he's been convicted and sentenced for sexually assaulting a minor.

In the TV mini-series about the NSU, Brandt speaks candidly about his double life. "Nothing alters the fact that we remember that time positively." You don't have to be ashamed of things that were done with political motives. Of course it created a bond between us. "And, I believe, no one would stab the other in the back."

The latest revelations on the informant front have prompted numerous reactions from politicians and joint plaintiff lawyers. Clemens Binninger, chairman of the second NSU Review Committee in the German Parliament, feels vindicated for his long-held skepticism. "I simply cannot imagine that not a single one of these informants knew where the trio was," the CDU politician told the DPA news service.

Victims' lawyer appeals to Merkel

Mehmet Daimagüler, a lawyer for the victims' relatives during the Munich trial, has demanded a reaction from the highest political levels. "We expect answers, even from Merkel."

In saying this, he is surely recalling a line spoken by the chancellor at a memorial service for the NSU victims in Berlin. "We will do everything we can to solve these murders."