The German Interior Ministry on Wednesday announced that hundreds of unsolved killings and attempted murders would need to be re-examined for far-right motives, following an initial police review.
A preliminary examination of 3,300 'cold' cases involving violent crime between 1990 and 2011 found that the question of a neo-Nazi motives remained in 746 of them, involving 849 victims.
"In a total of 746 cases across Germany there were leads in that direction," ministry spokesman Hendrik Lörges told reporters in Berlin.
"Let me stress that at the moment there are only indications that may not stand up to scrutiny," he said.
"We should wait and see in how many cases this gets verified," said Lörges.
News of the investigation, first reported by German daily newspaper the Neue Osnabrücker Zeitung on Wednesday, was welcomed by anti-racism campaigners.
Some 63 murders committed over the 21-year period in question are currently classified as far-right crimes. However, the Amadeu Antonio Foundation anti-racism campaign group, puts the true number at 184.
"This investigation is a positive move toward greater transparency," the foundation's chairwoman Anetta Kahane told The Associated Press. "Germany really needs to face up to the extent of far-right crime."
Green Party parliamentary leader Katrin Göring-Eckardt said on Wednesday that authorities had "completely misjudged" the true extent of extremist violent crime.
Germany was shocked by the revelation in 2011 that 10 unsolved murders, from 2000 to 2007, had a racist motive.
The killings of nine men of Turkish origin and one ethnically-Greek man, were initially linked to organized crime within the immigrant community. A German policewoman was also killed.
NSU murder series
Only in late 2011, did authorities conclude that the crimes had actually been carried out by the far-right National Socialist Underground (NSU).
The two suspects believed to have acted as gunmen in the killings, Uwe Mundlos and Uwe Böhnhardt, killed themselves following a failed bank raid in 2011.
A third alleged member of the group, Beate Zschäpe, is currently on trial in Munich over her suspected role in the killings.
The NSU case - subsequently examined by a parliamentary commission of inquiry, highlighted a series of intelligence failings that might have helped the group evade detection by domestic security services.
"There's no doubt that the NSU murder series exposed structural and organizational problems," said government spokesman Steffen Seibert on Wednesday.
Interior ministers of Germany's 16 states gathered Wednesday in Osnabrück, Lower Saxony, for an annual fall meeting, debating a bid to ban the far-right National Democratic Party (NPD).
rc/ipj (AFP, AP, dpa)