A doctor who is accused of organising the mass murder of at least 1,200 tops an updated list of the ten most wanted war criminal suspects wanted by an international Nazi hunting group.

"Operation Last Chance" was launched eight years ago by the Simon Wiesenthal Centre, the international Jewish rights group, to put pressure on governments to bring remaining suspected Nazi war criminals to justice before they die.

As the world marked the annual Holocaust memorial day on Monday, the Simon Wiesenthal Centre on Monday praised Germany for bringing accused Nazi war criminals John Demanjuk and Heinrich Boere to trial over the past year, but said a "lack of political will" continues to be the major obstacle to punishing others, particularly in post-communist Eastern Europe.

. Dr Sandor Kepiro, 95, lives freely in Hungary, accordingt to the group, but in wartime served in Serbia, where he took part in a massacre in Novi Sad in 1942.

Scores were shot along the Danube and dumped into the freezing water. Kepiro was sentenced to 10 years in prison in 1944, but was set free by Hungary’s fascist regime and fled to Argentina. Two years later, Hungary’s communist government convicted him of war crimes in absentia, but the Simon Wiesenthal Centre claims he returned to Hungary in 1996.

2. Milijov Asner, 96, a Croatian police chief who allegedly collaborated with the Nazis. He is accused of sending hundreds of Jews, gipsies and Serbs to death camps. By 1942, the entire Jewish community in Asner’s town, Pozega, was wiped out.

After the war, Asner moved to Austria, where he was granted citizenship. Some five decades later, he returned to Pozega, where he was discovered by a young historian. Asner promptly returned to Austria.

In 2005, Croatia requested extradition, but Austria denied the request on the basis of Asner’s citizenship. When it was discovered that he had lost his citizenship, Austria denied extradition on medical grounds.

3. Samuel Kunz, 89, lives in Germany and is accused of having served in the extermination camp of Belzec in occupied Poland, where 500,000 Jews were gassed. Kunz is alleged to have participated in the murders of 434,000 people during his time there as a guard.

4 Adolf Storms, an former SS officer, is accused of killing 58 Jews in March 1945 in the village of Deutsche Schuetzen in Austria.

Now 90, he allegedly forced victims to kneel beside an open pit before they were shot and tumbled into the mass grave. Charged in Duisburg, Germany, with the crime, the Wiesenthal Centre wants the process speeded up as ill health threatens to claim Storms’ life before he has answered for his actions in court.

5 Klaas Carl Faber, 88, is a Dutch national who served in the German Sicherheitsdienst, the Nazi SS intelligence service, in the Netherlands.

He was sentenced to death in Holland for murders of prisoners at the Westerbork transit camp; the staging post for Jews en-route to extermination centres in occupied Poland.

6. Karoly (Charles) Zentai, 98, a Hungarian-born resident of Australia, is fighting extradition to Budapest to face charges of the massacre of Jews there in 1944.

7 Soren Kam, 98, is accused of being responsible for the death of a Danish journalist and the round up of Danish Jews after her stole their registration books in Copenhagen. .

While in Germany, Kam has regularly attended veterans’ rallies of SS men. He has also been closely associated with Heinrich Himmler’s daughter Gudrun Burwitz and her network Stille Hilfe - “Silent Help” - set up to support arrested, condemned or fugitive former SS men.

8 Peter Egner, 98, is suspected of being a member of the mobile killing units operating in occupied Belgrade. The Simon Wiesenthal Centre believes he is connected to the deaths of 17,444 Jews, gypsies and communists. Serbia wants him tried there. He is currently fighting deportation from America, where he has lived since the 1950s.

9 Algimantas Dalide, 98, was extradited from America to Lithuania for his alleged part in the rounding up of the country’s Jews for murder during the Second World War. But he was spared prison on account of his age and health.

10 Michail Gorschkow, 96, a former Gestapo official in Estonia during the war, is accused of participating in the murders of 3,000 Jews in Russia.

He moved to America after the war, but left before being stripped of his citizenship in 2002. Since then, Estonia has been investigating his wartime activities without saying where he is.

In Germany this year Heinrich Boere, an 88-year-old Dutchman who murdered resistance men in The Netherlands in wartime was sentenced to life imprisonment in Germany. Currently underway in Germany is the trial of another former list entrant, John Demjanjuk, 89, who is accused of aiding in the murders of 27,900 Jews at the Sobibor death camp in Poland.

telegraph.co.uk