Holocaust survivor and Nazi-hunter Simon Wiesenthal has died in the Austrian capital, Vienna, aged 96.
Simon Wiesenthal survived the Nazi death camps of World War II
He was credited with helping to bring more than 1,100 Nazi war criminals to justice in the decades after the genocide of the Jews in World War II.
They included Adolf Eichmann, an architect of the Holocaust, and Franz Stangl, commandant of the Treblinka and Sobibor Nazi death camps in Poland.
His death was announced by officials at the US-based Simon Wiesenthal Center.
Mr Wiesenthal died in his sleep at his home, according to Rabbi Marvin Hier, dean and founder of the centre, which campaigns against anti-Semitism and other forms of intolerance.
"Simon Wiesenthal was the conscience of the Holocaust," Mr Hier said.
"When the Holocaust ended in 1945 and the whole world went home to forget, he alone remained behind to remember. He did not forget.
"He became the permanent representative of the victims, determined to bring the perpetrators of history's greatest crime to justice."
Israeli Foreign Ministry spokesman Mark Regev said: "Simon Wiesenthal's passing saddens us all. He was a champion in the fight to bring to justice the 20th Century's worst criminals who had escaped justice.
"And in that effort, Wiesenthal earned the respect and the recognition of the state of Israel, of the Jewish people and of everyone... who supports the fight against racism, and injustice."
The director of the Wiesenthal Centre in Jerusalem, Ephraim Zuroff, described him as a "real Jewish hero" and praised those continuing to work to bring war criminals to justice.
"We have a list of 10 Nazis we are continuing to look for actively," he told Israeli radio.
Mr Wiesenthal, who grew up in Ukraine, was a prisoner in the Mauthausen death camp when it was liberated by US troops in May 1945, but dozens of his family members - including his mother, stepfather and stepbrother - died in the Holocaust.
In the 1950s, he helped to track down Eichmann in Argentina.
In 1960, Eichmann was abducted there by Israeli agents and subsequently tried, convicted and executed in Israel.
Mr Wiesenthal went on to establish the Jewish Documentation Center in Vienna to track down war criminals.
It located Stangl in Brazil. He was sentenced to life imprisonment in Germany in 1967 and died in prison.
Another high-profile case involved Hermine Ryan, a housewife living in Queens, New York, whom he accused of supervising the killings of hundreds of children at Majdanek camp.
She was extradited to Germany for trial as a war criminal in 1973 and received life imprisonment.
Mr Wiesenthal's biggest disappointments were his failures to secure the capture of Gestapo chief Heinrich Muller and Auschwitz doctor Josef Mengele.
Six million Jews were murdered in the Nazi death camps of World War II, along with thousands of Gypsies, homosexuals, disabled people and political dissidents.