Prof. Shlomo Sand, a Tel Aviv University history professor, said Sunday that he had received an envelope containing white powder and a letter that included death threats.

In the letter, which was received by the secretary of the university's Department of History, the professor was accused of being an "anti-Semitic," among other things. The letter also threatened Sand that he would "not live much longer."

In a conversation with Haaretz, Sand said, "I opened a series of letters as usual, and then all of a sudden a white cloud jumped out. I was shocked that the powder got on to my hands and threw down the letter. It's been brought to the attention of the security officer and the police sent a squad car to the site and the substance was taken for a test."

Sand, who intends on filing a complaint with Israel Police on Monday, said he was concerned after having received the letter. "They wrote that I'm an anti-Semite, Nazi, that my time will come. It's a very unpleasant feeling," he said.

The history professor said it was possible that his new book, " The Invention of the Land of Israel: From Holy Land to Homeland," might have been what caused someone to send him the letter. "Four years ago, when I published my previous book, 'The Invention of the Jewish People,' there were fewer crazy people than there are today," Sand told Haaretz.

Throughout the day, the police examined the substance and discovered it was not of a chemical nature. The police also opened an investigation into the case.

In Sand's book on the Jewish people, the author attempts to prove that the Jews now living in Israel and other places in the world are not at all descendants of the ancient people who inhabited the Kingdom of Judea during the First and Second Temple period. Their origins, according to him, are in varied peoples that converted to Judaism during the course of history, in different corners of the Mediterranean Basin and the adjacent regions. Not only are the North African Jews for the most part descendants of pagans who converted to Judaism, but so are the Jews of Yemen and the Ashkenazi Jews of Eastern Europe.