Interior Minister Giuliano Amato said the probe would be aimed at verifying the existence of the blog, which the ANSA news service said alleges that the scholars had banded together as a "lobby."

Italian law prohibits anti-Semitism. Some of the professors on the list were demanding that the blog and others like it be shut down.

"'We are on the borderline of madness," said Anna Foa, a Rome history professor. "A list of names, together with anti-Semitic slogans, represents an evolution which is truly frightening."