A poster campaign has been launched in Germany that aims to find the last surviving war criminals from World War II.

Posters will go up in Berlin, Hamburg and Cologne to enlist the help of the public in tracking down suspects.

"Operation Last Chance II" is the name given to the Simon Wiesenthal Centre's publicity campaign.

Rewards of up to €25,000 are on offer for information as part of the campaign.

Campaigners have been encouraged by the prosecution last month in Hungary of 98-year-old Laszlo Csatary for helping to deport Jews to Auschwitz and by the arrest in Germany of Hans Lipschis, a suspected former guard at the Auschwitz concentration camp.

The posters feature a black and white photograph of the notorious "Gate of Death" at the Auschwitz-Birkenau extermination camp.

The slogan "Late, but not too late" is emblazoned across it.

"This is really it. We have two or three years maximum, that's all," Efraim Zuroff, head of the Israel office of the Simon Wiesenthal Centre said.

The search is no longer focused on high-level perpetrators of the Holocaust, in which six million Jews were killed, but for thousands of people who were involved in the process.

Mr Zuroff said around 60 individuals could be alive and fit to go on trial.

The impetus for a handful of new investigations came from the landmark conviction in Munich in 2011 of Sobibor camp guard John Demjanjuk.

He was the first Nazi war criminal to be convicted in Germany without evidence of a specific crime or a victim but on the grounds that he was a guard at a death camp.

"Germany has a well-developed consciousness of Nazi criminality. It is one of the few countries where family members ring up with information on relatives," said Mr Zuroff.

The centre declined to say how much the campaign cost, but said the funding came mainly from private donations.

On its list of most wanted Nazi war criminals is Gerhard Sommer, 92, a former member of Hitler's SS Division suspected of being involved in the massacre of 560 civilians in Italy.

Another is Soeren Kam, who the centre says served as an officer in the SS Viking Division and took part in the murder of a Danish anti-Nazi newspaper editor.

Although an international military tribunal put some of the most infamous Nazi leaders on trial soon after World War II in the Nuremburg Trials, Germany has a patchy record on bringing its Nazi war criminals to justice.

In the last few years, however, prosecutors in some parts of Germany have actively sought out some of the last survivors.