But by cultivating his contacts with German and Vichy officials, Mr Sardari somehow managed to win exemptions from Nazi race laws for at least 2,000 Iranian Jews by arguing that they did not have blood ties to European Jewry.
He claimed that despite the fact that some Iranians had followed the teachings of the Prophet Moses for thousands of years, they had always been of Iranian stock and therefore were “Mousaique” – Moses followers, which he dubbed “Djuguten” – and not part of the Jewish race.
The book includes archives of Nazi official correspondence seeking “expert opinion” on his claims. The racial purity specialists said that deeper research was necessary on the Iranian sect, which the book suggests may have been Mr Sardari’s invention, to ascertain whether its followers were Jewish or not.
His other trump card was a new-style Iranian passport, created by the new regime in Iran in 1925 but which most Europe-based Iranians did not possess. The new identity papers made it much easier to travel across Europe.
His task became even more dangerous when Britain and Russia invaded Iran in September 1941, when he was ordered by Tehran to return home as soon as possible after it signed a treaty with the Allies. But he stayed on regardless, using instead inheritance money to keep his office going after being stripped of his diplomatic immunity and pay.
By December 1942, Adolf Eichmann, the senior Nazi in charge of Jewish affairs, pronounced his argument “the usual Jewish tricks and attempts at camouflage”, in a letter published in Mr Mokhtari’s book.
But Mr Sardari soldiered on, helping families escape from Paris just as tens of thousands of Jews were being deported from France to death camps.
Eliane Senahi Cohanim was seven when she fled France with her family.
Mr Sardari provided them with the passports and travel documents they needed for safe-passage out of Europe, which took a month.
“I think he was like Schindler, at that time, helping the Jews in Paris,” the 78-year old told the BBC from her home in California.
Mr Sardari neither sought nor received much recognition for his efforts in his lifetime and died lonely in a bedsit in Croydon, south London, in 1981.
He had lost his ambassador’s pension and Tehran properties in the Iranian revolution.
His humanitarian work was belatedly recognised in 2004 at a ceremony at the Simon Wiesenthal Centre in Los Angeles.
The author Fariborz Mokhtari said he hoped that the story, and the testimony of survivors, would help undo “popular misconceptions” about Iran and its people and show the “general cultural propensity of Iranians to be tolerant”.
“Here you have a Muslim Iranian who goes out of his way, risks his life, certainly risks his career and property and everything else, to save fellow Iranians,” he says.
“There is no distinction ‘I am Muslim, he is Jew’ or whatever.”
[Image: Abdol-Hossein Sardari was a junior Iranian diplomat in 1940.]