Heinz Fromm, head of the Office for the Protection of the Constitution (BfV), Germany’s domestic intelligence agency, said that there is an increasing risk of violence by far-right extremists inspired by the actions of the National Socialist Underground (NSU), The Telegraph reported.
The three-person gang murdered nine men of immigrant background and a policewoman between 2000 and 2006 and carried out a string of bombings and bank robberies in Germany's worst outbreak of home-grown terrorism since 1980.
Presenting an annual national security report prepared by his agency, Mr Fromm said "individuals could take these acts as an inspiration, and act in a similar manner," asserting that "great vigilance was needed".
The report also stressed that there is an increasing risk of violence "by self-radicalized individuals or small groups" from the far right.
Fromm's warning comes amid increasing concern in Germany over the threat posed by neo-Nazi extremists.
Initial astonishment in Germany over the extent of NSU's actions and the total failure of the police and intelligence services to catch them, has been compounded by recent scandals that have fuelled conspiracy theories that the group enjoyed the protection of some in the intelligence community, according to The Telegraph.
Earlier this month it was revealed that the BfV had shredded key case files on NSU, and that a secret agent may have been present at one of the murders but failed to take any action.
The National Socialist Underground is suspected of killing eight Turkish men and a Greek between 2000 and 2006 and a policewoman in 2007 in attacks across the country. For years, authorities suspected organized crime rather than racist violence.