Benjamin Ferencz

Benjamin Ferencz was 27 when he obtained the convictions of Nazi officers for war crimes and crimes against humanity.

After the war, he continued his work as a lawyer and dedicated his life to fighting for the rights of victims of war crimes and genocide.

He played a key role in the establishment of the International Criminal Court, the first permanent international tribunal to prosecute war crimes, crimes against humanity, and genocide.

He died in his sleep on Friday evening at an assisted living facility in Boynton Beach, Florida. The US Holocaust Museum said the world had lost “a leader in the quest for justice for victims of genocide”.

His son, Donald Ferencz, who also works in international law, told the BBC he would remember his father as someone who had dedicated his life to “trying to make it a more humane world under the rule of law”.

“He’d seen and experienced things which were so horrific that they fuelled the passion which took him not only through the court at Nuremberg but fuelled really the rest of his life”, he said.

He added: “This is not a guy who went fishing or played golf. This is a guy whose life mission was to try to make it a better world.”

Mr Ferencz was born in Transylvania, part of Romania, in 1920. His family emigrated to the US when he was young in order to escape anti-semitism, ultimately settling in New York.

He graduated from Harvard Law School in 1943 and was enlisted in the U.S. Army during World War Two. He took part in the Normandy landings and the Battle of the Bulge and eventually joined a team given the job of investigating evidence of Nazi war crimes.

He spoke of finding bodies “piled up like cordwood” and “helpless skeletons with diarrhoea, dysentery, typhus, TB, pneumonia, and other ailments, retching in their louse ridden bunks or on the ground with only their pathetic eyes pleading for help”.

Buchenwald, one of the largest concentration camps inside Germany, was, he said, a “charnel house of indescribable horrors”.

“There is no doubt that I was indelibly traumatised by my experiences as a war crimes investigator of Nazi extermination centres,” he wrote. “I still try not to talk or think about the details.”

He returned to New York after the war to practise law but was recruited to prosecute the Nazis at Nuremberg. He became chief prosecutor at the trial of members of the Einsatzgruppen – mobile SS death squads that roamed Eastern Europe and are estimated to have murdered more than a million people.

He is survived by a son and three daughters.