Jewish groups welcomed the conviction Wednesday of a former Nazi SS officer known as the "Bookkeeper of Auschwitz" and urged justice authorities to maintain pressure on ageing war criminals.
Seven decades after World War II, a German court sentenced Oskar Groening, 94, to four years in prison for accessory to the murder of 300,000 Hungarian Jews sent to the death camp's gas chambers in 1944.
"Albeit belatedly, justice has been done," World Jewish Congress (WJC) president Ronald Lauder said in a statement.
"Mr. Groening was only a small cog in the Nazi death machine, but without the actions of people like him, the mass murder of millions of Jews and others would not have been possible."
Lauder said that despite the passage of time and the advanced age of the defendant "there must never be impunity or closure for those who were involved in mass murder and genocide."
He called on authorities in Germany and across Europe "not to relent in the quest for bringing the perpetrators of the biggest crime in the history of mankind to justice."
The Nazi-hunting Simon Wiesenthal Center said it hoped Groening's conviction would "pave the way for additional prosecutions of individuals who served in death camps and the special mobile killing units."
"It is abundantly clear that the window of opportunity to bring Holocaust perpetrators to justice will soon be closed, which makes the expedition of these cases of exceptional urgency," said the director of its Jerusalem office, Efraim Zuroff.
He urged the German government to make resources available for investigations and justice authorities to give "first priority" to such cases.
The head of Germany's 200,000-strong Jewish community, Josef Schuster, called the verdict "very important" and blasted the country's justice system for "drawing out or obstructing such cases for decades."
Schuster thanked the more than dozen elderly Auschwitz survivors who testified about the atrocities they witnessed and endured.
"The trial once again showed German society the crimes of the Shoah and that the victims are still suffering decades later," Schuster said, adding that he hoped more former Nazis would still face justice.
Groening worked as an accountant at Auschwitz in Nazi-occupied Poland, sorting and counting the money taken from those killed or used as slave labor, and sending it back to his Nazi superiors in Berlin.
The court in the northern city of Lueneburg acknowledged that he had only been a "cog in the wheel" at the camp but that it had taken thousands of such people to keep running "a machinery designed entirely for the killing" of human beings.
Presiding judge Franz Kompisch called it "scandalous" that it had taken so long for the German justice system to prosecute such cases.
He said that after a "judicial heyday" in the 1960s in which Auschwitz trials brought home to Germans the crimes committed in their name, prosecutors and courts failed to commit the necessary resources to such "complicated" cases.
He noted that of 6,500 people who worked at Auschwitz known to authorities, only 49 were ever convicted after the war. Groening is now the 50th.
Addressing the purportedly new German legal basis for bringing ex-Nazis to justice, the 2011 trial of former death camp guard John Demjanjuk, Kompisch argued that the existing murder law would have allowed many more convictions.
While previously courts had punished defendants for individual atrocities, Demjanjuk was judged solely on the basis of having worked at the Sobibor camp in occupied Poland.
He died in 2012 before his appeal could be heard.
The head of the federal office investigating Nazi-era crimes, Kurt Schrimm, told the Bild newspaper this month that other probes of former concentration camp guards were still ongoing.
But he said "many had to be terminated because the accused had died or were no longer capable of standing trial."