But Dr Efraim Zuroff - who has often been bestowed with the title Nazi Hunter - insists what he does is not for personal satisfaction.

New York-born Dr Zuroff is director of the Jerusalem-based Simon Wiesenthal Centre.

Speaking exclusively to the Jewish Telegraph during a three-day visit to Manchester, he said: "I have no personal interest in these Nazis. What I do is for the good of the Jewish people.

"Simon Wiesenthal's biggest worry was that the Holocaust would be forgotten.

"Mine is that there is so much written about the Holocaust, that the Shoah will end up being distorted."

The 60-year-old, who describes himself as one-third detective, one-third political lobbyist and one-third historian, is the co-ordinator of the Nazi war crimes research worldwide for the centre, whose headquarters are in Los Angeles.

Six years ago, Dr Zuroff launched Operation Last Chance, which offers financial rewards for information which leads to the prosecution and punishment of Nazi war criminals.

The project has been initiated in most eastern European countries, as well as Croatia, Hungary and Germany.

And to date it has yielded three arrest warrants, two extradition requests and numerous criminal investigations.

He explained: "The biggest problem we have is the lack of political will within some countries' governments. Many of them refuse to acknowledge their past in helping to kill Jews."

Among the countries which have failed to help Dr Zuroff include Norway, Sweden and, not surprisingly, Syria.

Nazi Alois Brunner, who was responsible for the deportation of more than 100,000 Jews from Austria, Slovakia, France and Greece, is believed to have lived in Syria for decades.

The Syrian authorities have refused to co-operate, although he has been convicted in absentia by France.

Dr Zuroff's captures includes Croatian Dinko Šakic, in 1998.

"I used the Holocaust records at Yad Vashem in Jerusalem years before they were made available to the public," Dr Zuroff added.

Šakic was a commander at the Jasonovac concentration camp during the Second World War.

Šakic was extradited from his home in Argentina, judged and found guilty by a Croatian court and sentenced to 20 years in prison. He died in July.

Dr Zuroff said: "I have had lots of threats from members of the Croatian community living in Australia.

"Unfortunately, there are still elements of support within Croatia for the Ustase."

As well as Jews, many Serbs also died at Jasonovac, and the country's President Boris Tadic nominated Dr Zuroff for the Nobel Peace Prize.

Dr Zuroff helped to track down Hungarian Karoly Zentai, who also lives in Australia.

He took part in the murder of Jews in Budapest in 1944 and Hungary asked for his extradition in 2005, but Zentai is currently appealing against it.

Some 130 work for the Wiesenthal Centre and they have people "on the case" in countries around the world, especially in Argentina.

Dr Zuroff explained: "After the Holocaust, Argentinian President Juan Peron and his wife Evita actually invited Nazis to live and settle there.

"Some Arab countries, like Egypt, invited Nazi scientists to work for their governments."

Dr Zuroff moved to Israel in 1970 after completing a degree in history at Yeshiva University, New York, followed by an MA in Holocaust studies at the Institute of Contemporary Jewry at Jerusalem's Hebrew University.

While at the university, Dr Zuroff completed his PhD, chronicling the response of Orthodox Jewry in America to the Holocaust.

He explained: "When I was growing up in New York, it was not long after the Holocaust. There was hardly any discussion or mention of it.

"I came to live in Israel because Israel is the antithesis of the Holocaust."

Dr Zuroff returned to Los Angeles to work for the centre and he played a leading role in establishing its library and archives.

He went back to Israel in 1980 where he served as a researcher for the American Justice Department's Office of Special Investigations.

He assisted in the preparation of cases against numerous Nazi war criminals living in America. Dr Zuroff continued: "America and Britain have always been excellent in their help in tracing Nazis.

"But Scotland Yard closed down their unit a couple of years ago. They said they had run out of cases." There are still eastern Europeans, especially Lithuanians, Latvians and Belarussians, living in Britain and suspected of killing Jews during the Holocaust.

They include Szymon Serafinowicz, Latvian Pauls Reinhards and Lithuanian Jaozas Dammsevicins.

Belarussian Serafinowicz has already been brought to trial, as was the late Lithuanian Anton Gekas, who lived in Edinburgh.

Dr Zuroff said: "People ask me 'when you find these people, why don't you kill them?'. But can you imagine the reaction in the media?

"We cannot execute people who are in their nineties, but we can bring them to justice."

He traced Sandor Kepiro, a Hungarian gendarmerie officer, who participated in the murder of more than 1,200 civilians in Novi Sad, Serbia, thanks to an email from a man in Scotland.

Dr Zuroff explained: "I had an email three years ago from a Scottish non-Jewish guy whose girlfriend was Hungarian.

"He went with his girlfriend to events in Scotland arranged by the Hungarian community there. At one of these events, he heard an old guy bragging about how he deported Jews to Auschwitz during the war.

"This guy had changed his name in the UK, so I asked the Scottish man to try and get me his real name, as well as his birthdate."

Dr Zuroff looked up more records at Yad Vashem, but could not find anything.

He spoke to a journalist who interviewed the Hungarian, pretending he was writing about the Hungarian community in Scotland. At his home the reporter saw a picture of a Hungarian officer on the wall - and was told that it was Kepiro.

Dr Zuroff contacted a Hungarian affairs expert at Yad Vashem, and found out that Kepiro, 94, was living in Budapest - opposite a shul.

Hungary has recently opened a new criminal investigation against him.

Other names on the most wanted list include Aribert Heim, who was a doctor in various concentration camps, Ivan Demjanjuk, who participated in the mass murder of Jews in Sobibor and Milivoj Asner, who deported hundreds of Jews in Croatia.

Married to Elisheva, he has four children and four grandchildren. His parents, Rabbi Dr Abraham and Mrs Esther Zuroff live in London.

Dr Zuroff spoke at a lunch to raise funds for the Nicky Alliance Day Centre, before addressing a gathering at South Manchester Synagogue, Bowdon, on Monday night.