[W.Z. The Holocaust Industry at its best!]

BERLIN -- In a final quest to bring Holocaust participants to justice, German authorities have reopened hundreds of dormant investigations of Nazi death camp guards -- men who are now so old that time has become "the enemy" for prosecutors hurrying to prepare cases.

The efforts could result in new prosecutions nearly seven decades after World War II.

Special Nazi war-crimes investigators reopened the files after the conviction of former U.S. autoworker John Demjanjuk, whose case set a new legal precedent in Germany. It was the first time prosecutors had been able to convict someone in a Nazi-era case without direct evidence that the suspect participated in a specific killing.

Now authorities are weighing whether the same approach could be used to pursue others, said Kurt Schrimm, the prosecutor who heads the investigation unit.

Given the advanced age of the suspects, investigators are not waiting until Demjanjuk's appeals are decided.

"We don't want to wait too long, so we've already begun our investigations," Schrimm said.

Elan Steinberg, vice president of the American Gathering of Holocaust Survivors and their Descendants, welcomed the news and urged prosecutors to act quickly.

"As our numbers -- those of the victims -- have also rapidly dwindled, this represents the final opportunity to witness justice carried out in our lifetimes," he said. "Time is the enemy here."

Meanwhile, the Simon Wiesenthal Center's top Nazi-hunter, Efraim Zuroff, said he would also launch a new campaign in the next two months to track down remaining Nazi war criminals. He said the Demjanjuk conviction has opened the door to prosecutions he never thought possible before.

"It could be a very interesting final chapter," he said by phone from Jerusalem. "This has tremendous implications even at this late date."

Demjanjuk, now 91, was deported from the U.S. to Germany in 2009 to stand trial. He was convicted in May of 28,060 counts of accessory to murder for serving as a guard at the Sobibor death camp in Nazi-occupied Poland.

Munich prosecutors argued that if they could prove that he was a guard at a camp like Sobibor -- established for the sole purpose of extermination -- it was enough to convict him of accessory to murder.

After 18 months of testimony, a Munich court agreed, finding Demjanjuk guilty and sentencing him to five years in prison. He denies ever being a guard and is currently free in southern Germany while appealing the conviction.

Schrimm said his office is going over all its files to see if any other cases fit into the same category as Demjanjuk. He estimated there are probably fewer than 1,000 possible suspects in Germany and abroad who are alive and can still be prosecuted. He would not give any names.

"We have to check everything -- from the people who we were aware of in camps like Sobibor ... or also in the Einsatzgruppen," he said, referring to the death squads responsible for mass killings, particularly early in the war before the death camps were established.

Prosecutors have not yet tested whether the Demjanjuk precedent could be extended to guards of Nazi camps where the sole purpose was not necessarily murder but where thousands of people died anyway.

Even the narrowest scenario -- looking at the guards of the four death camps used only for killings: Belzec, Sobibor, Chelmno and Treblinka -- plus those involved in the Einsatzgruppen could lead to scores more prosecutions, Zuroff said.

He estimated the number of suspects at 4,000.

"Even if only 2 percent of those people are alive, we're talking 80 people. And let's assume half of them are not medically fit to be brought to justice. That leaves us with 40 people, so there is incredible potential," he said.

Immediately after the war, top Nazis such as Hermann Goering were convicted at trials run by the Allies.

Investigations of the lower ranks eventually fell to German courts. But there was little political will to aggressively pursue the prosecutions, and many of the trials ended with short sentences or acquittals of suspects in positions of greater responsibility than Demjanjuk.

However, the current generation of prosecutors and judges in Germany has shown a new willingness to pursue even the lower ranks.

"Our goal is to bring as many people to justice as possible," Zuroff said. "They shouldn't be let off if they're less than Mengele, less than Himmler ... in a tragedy of this scope."

Working in favor of the new investigators is the fact that most suspects have probably lived openly under their own names for decades, thinking they had nothing to fear.

Those who are harder to locate will be the focus of the Wiesenthal center's efforts, which Zuroff said would include reward money for information that helps find a suspect.

Schrimm acknowledged that Demjanjuk's appeal, if granted, could threaten any new prosecutions. The appeal could still take a year or longer. And the suspects are not getting any younger.

"That's why we're preparing everything now so that as soon as there is a final decision, we can move immediately with charges," he said.

Zuroff said he hoped the appeal could somehow be expedited so new charges against others could be filed before it is too late.