Although they were being paid to deliver information to the authorities, the snitches failed to stop members of the National Socialist Underground – Uwe Mundlos, Uwe Böhnhardt and Beate Zschäpe – from disappearing after their bomb-making operation was uncovered in 1998.
The Thüringia state Verfassungsschutz had Tino Brandt, leader of the regional illegal neo-Nazi group Thüringer Heimatschutz, in their pay, along with the head of the state's neo-Nazi group Blood and Honour, the magazine reported online on Saturday.
Mundlos and Böhnhardt are thought to have embarked on their killing spree in 2000, shooting dead what would be the first of what would be nine shopkeepers of Turkish and Greek ethnicity over the following six years. They are also said to have murdered a policewoman in 2007.
At least one bomb attack is also being attributed to the group, who also carried out bank robberies to fund their lives in hiding based at a flat in Zwickau, Saxony.
This ended earlier this month when Mundlos and Böhnhardt killed themselves in a caravan after being stopped by police. Zschäpe handed herself in to the police shortly after allegedly blowing up the flat the three had shared. Another man was also arrested, suspected of helping them.
Although the Federal Public Prosecutor said on Friday that he thought a total of six people had been involved in the NSU, the Thüringia Verfassungsschutz is also speaking of around 20 people in the neo-Nazi underground who helped the group.
This could include a man named only as André E., whose company Aemedig has expertise in video editing, Der Speigel reported. A flyer from his company was found in the rubble of the trio's flat. Mundlos, Böhnhardt and Zschäpe are not considered to have been skilled enough to have made the video charting the murders which was also found in the flat.
Train discount cards in the names of André E. and his wife were found in the caravan in which Mundlos and Böhnhardt killed themselves – although it appears the cards were used by Böhnhardt and Zschäpe.
Around 400 police officers have been assigned to the case, according to Focus magazine on Saturday.
President of the federal police, Jörg Ziercke, told the magazine the police had not completely failed, but that the group had behaved untypically, in that they had never claimed responsibility for their crimes.
Chancellor Angela Merkel called for authorities to work more effectively together, and lessons to be learned from their failure to stop the group.
“I never want a secret service to have total power again. But the authorities have to inform each other, of course,” she said in a weekly podcast.
Interior Minister Hans-Peter Friedrich has called for the federal prosecutor to have increased powers to be able to take on a case, particularly when a criminal case crosses state borders, according to Der Spiegel on Saturday.