German officials said Tuesday that a network of supporters may have helped an underground neo-Nazi group suspected of murdering eight Turks, a Greek and a policewoman over the past decade.
The investigation into the activities of the so-called National Socialist Underground has spiraled into a nationwide search into previously unsolved crimes, including suspected terror attacks in Cologne and Duesseldorf from 2000 to 2004, that injured more than 30 people, most of them foreigners.
Two people have been arrested, a suspected co-founder of the group and an alleged supporter. Two other suspected members died last week in an apparent suicide, but authorities believe the group relied on a much larger network of "helpers" across the nation.
"Those who helped the terrorists must be found and severely punished," opposition lawmaker Thomas Oppermann, who heads the German parliament's intelligence committee, told reporters. "There are leads on other supporters," Oppermann said, but refused to elaborate, citing the ongoing investigation.
The case has sparked anger and dismay among Germans and raised questions about how a far-right extremist group whose members were at one time known to authorities was able to slip underground and carry out a series of xenophobic attacks.
Questions also swirled around a long-standing practice of the nation's domestic intelligence agency to employ members of the far-right scene as informants, amid reports that such informants might have known about the extremists or their whereabouts.
Oppermann said authorities in Hesse investigating the 2006 slaying of a Turkish internet cafe owner _ now believed to be the group's last murder victim _ have determined that an employee of the state's domestic intelligence agency was at the cafe before the crime was carried out.
"A further investigation into this person showed that he had a strong pull to the far-right and has, in the meantime, been suspended," Oppermann said. However, the intelligence employee's case has been known for a long time, and investigators have never charged the person because they lacked sufficient evidence.
The group, which is believed to have carried out numerous bank robberies to finance its operations, has vaunted itself for the committed murders in a cruel propaganda DVD found by investigators.
Suspected co-founder, 36-year-old Beate Z., who turned herself in last week and was formally arrested on Monday, has so far refused to speak with police.
The case has sparked a fierce debate over the government's ability to protect the millions of immigrants who call Germany home, even as it seeks to attract more skilled workers from abroad.