Sandor képiró, who died last Saturday, had recently been acquitted by the Buda District Court of complicity in a 1942 massacre of 1,250 civilians, including Jews, Serbs and Roma, in the Serbian city of Novi Sad.

Before the Budapest trial, Képiró had twice been found guilty of involvement in the massacre; once by the pre-Nazi Hungarian courts, and again after the war, in 1946, in absentia. By then, he had fled via Austria to Argentina.

He returned to Budapest in 1996, where the Wiesenthal Centre's Israel director Efraim Zuroff, who had been searching for Nazi war criminals under the Wiesenthal Centre's 'Operation Last Chance' programme, located him. Képiró's name had been at the top of a list of most-wanted suspects.

Mr Zuroff said: "Kepiro's death while the appeal of his acquittal was pending underscores the need to expedite such cases. I feel a deep sense of frustration, but I will continue my efforts since there are additonal cases which can still be brought to justice."