The trio known as the National Socialist Underground (NSU) are thought to be responsible for ten murders, two bomb attacks and a number of bank raids. The Thuringia legislature has just published the findings of a committee that examined the reasons for the many failures in the official search for the NSU, from the time they went underground in 1998 until their last bank raid in Eisenach in November 2011.

Spotted by the police after that raid, Uwe Böhnhardt and Uwe Mundlos took refuge in a caravan in which they were found dead, having apparently killed themselves to avoid arrest. Some committee members were not convinced they had committed suicide. But that is just one of the mysteries likely to go unsolved. A day later, the third member of the NSU, Beate Zschäpe, set fire to the flat where they had lived together and walked into the local police station to give herself up.

The report published on Thursday in Erfurt makes no bones about its major findings: ‘The series of mistakes, unfulfilled decisions and non-compliance with basic standards during the investigations leads to the suspicion of targeted sabotage and a deliberate thwarting of efforts to find these fugitives.’

The security services had been watching the NSU since 1998. Known neo-Nazis with long criminal records, they had rented a garage near their flat to make bombs in. The police were planning to raid the garage, but somebody warned the bombmakers and they skipped off into hiding.

All ten murder victims – eight Turkish businessmen, one Greek and a policewoman in Heilbronn – were shot with the same gun, but nobody in the police or security services made the connection. Five of the killings took place in Bavaria; the police said it was a Turkish underground feud. The press called them the ‘Döner Murders’.

The owner of an internet café in Kassel was shot while an agent of the local security service was there drinking a cup of coffee. He saw nothing, heard nothing, and it was only with the greatest reluctance that his bosses gave permission for him to make a statement, which was worse than useless to the investigating committee.

According to the 1880-page Thuringia report, documents have been shredded or gone missing and hard drives have been erased. Commentators have said there must have been direct complicity between the NSU trio, their network of helpers and the security forces in Thuringia and Bavaria. One leading neo-Nazi, who acted as an undercover agent for the Erfurt authorities, was paid more than 200,000 DM without ever having to account for the outlay. He was in almost daily contact with the NSU trio but supposedly unable to give any assistance to his handlers on their activities. The committee found this difficult to believe.

Zschäpe has been on trial in Munich for more than a year. During the 180 days of proceedings she has not said a single word in court. She recently tried to fire her defence lawyers, but the judge was having none of it – that would have meant ditching the whole trial and starting again. Zschäpe is charged with 10 counts of murder, 25 counts of attempted murder, 10 counts of robbery, extortion and membership in a terrorist organisation. The German security services stand accused by the Thuringia report of deliberately sabotaging attempts to apprehend the NSU suspects; they aren't saying anything either.