Milivoj Asner, the world's third most wanted Nazi war criminal, died last week in the Austrian city of Klagenfurt, aged 98.
The Simon Wiesenthal Centre rated him at 'number three' on their wanted list for overseeing the deportation of hundreds of Jews, Serbs and gypsies while serving as a police chief in Croatia during the Second World War.
He changed his name to Georg Aschner when he fled to Austria in 1945.
In 2005, the Croatian government charged Asner with committing war crimes in Pozega, Slovenia, and requested his extradition, but an Austrian court argued he was unfit to stand trial because he had senile dementia.
In a statement issued on Monday, the Simon Wiesenthal Centre condemned Austria for not acting to convict the Nazi collaborator.
Efraim Zuroff, director of the Simon Wiesenthal Centre office in Jerusalem, said: "Milivoj Asner played a key role in the persecution and deaths of hundreds of Jews, Serbs and Roma in his position as the Ustasha police chief, and his criminal responsibility for their fate is absolutely clear.
"His recent death in Austria, unprosecuted for his crimes, is a travesty of justice which reinforces the total failure of the Austrian authorities to adequately deal with the issue of Nazi war criminals over the past three decades."