Al-Qaida's American spokesman said in a message released over the weekend that his grandfather was Jewish and encouraged him to visit Israel and meet relatives there.
Adam Gadahn, who was raised in California, spent much of the 34-minute speech discussing Israeli attacks on the Gaza Strip late last year and calling on Palestinians to continue fighting.
"My grandfather was a Zionist and a zealous supporter of the usurper entity and a prominent member of a number of Zionist hate organizations. He used to repeat to me what he claimed are the virtues of this entity and encourage me to visit ... where relatives of ours live," Gadahn said in fluent Arabic in the recording produced by al-Qaida's media arm and posted Saturday on an Islamic Web site.
Gadahn, also known as Azzam al-Amriki, was charged with treason in the U.S. in 2006 and has been wanted since 2004 by the FBI, which is offering a $1 million reward for information leading to his arrest or conviction.
Gadahn said his grandfather gave him Israeli Prime Minister Benjamin Netanyahu's book "A Place Among The Nations," which discusses the Arab-Israeli dispute.
"He puts forth his feeble arguments and unmasked lies to justify the Jews' rape of Muslim Palestine," Ghadan said of the book.
Gadahn who tore up his American passport in a video released last year, said he did not respond to his grandfather's call to take Israeli citizenship "despite my young age at the time and the fact that I was not yet a Muslim ... perhaps that this is from Allah's kindness to me and His taking care of me."
Gadahn, who has appeared in several previous videos, is the first American to be charged with treason in more than 50 years and could face the death penalty if convicted. He also was indicted on a charge of providing material support to terrorists.