Israel regards Ismail Haniyeh, the Palestinian Hamas prime minister, as an enemy of state. But three of his sisters enjoy full Israeli citizenship, having moved 30 years ago to the desert town of Tel Sheva.
Some of their offspring have even served in the Israeli army, the force responsible for decades of Israeli occupation in Gaza and the West Bank, an occupation that the Islamist movement, Hamas, was founded to fight.
The Daily Telegraph tracked down the Haniyeh sisters, Kholidia, Laila and Sabah, to a town in southern Israel. That they live in Israel is a closely guarded secret and nowhere is it guarded more secretly than Tel Sheva, a town inhabited mainly by Israeli Bedouin on the edge of the Negev desert.
"There is no reason to speak to my wife,'' said Salameh Abu Rukayek, 53, who married Kholidia. "It is private business and you are not welcome asking questions about my wife.''
Perhaps he felt discussion of his wife's family links might jeopardise his relatively comfortable lifestyle.
Bedouins form a small and poor minority in modern Israel, descendants of desert nomads who roamed the Holy Land in ancient times, living in tents and travelling by camel train. Some Bedouin have settled down in towns such as Tel Sheva and many make a good living, often running transport firms across Israel.
Although they regard themselves as separate from Palestinians, links between the two communities are nevertheless close. Both share the same Muslim faith.
Another member of the clan, Yousef Abu Ruqia, 50, who works as secretary in the municipal council, explained how the Haniyeh sisters came to Tel Sheva.
"In a small community like ours there were not enough women to go round, so some of the men would go and look for wives elsewhere,'' he said.
"The Haniyeh sisters were Palestinians living in Gaza. Back then it was possible for people to visit Gaza easily, so Kholidia was the first to be married and move to Tel Sheva, and then Laila and then Sabah.''
He said he remembered the time, 25 years ago, when their younger brother, Ismail, would come to visit his sisters.
"There was another brother, Khaled, who came here to work laying tiles and each year, at the holiday after Ramadan, Ismail would come and visit his brother and sisters."
The issue of Palestinian-Israeli links recently received close scrutiny from the Israeli supreme court, which was asked to consider the legality of a new law banning Palestinians from joining their Israeli spouses. The court accepted the state's argument that security concerns justified keeping couples apart if they married across the divide.
While the law is intended to address current political problems, the presence of a Hamas leader's own family in Israel reveals the extent and strength of links in spite of decades of mutual hostility.
Mr Abu Ruqia said the law banning Palestinian women over 25 and men over 35 from applying to join their spouses in Israel would have stopped the Haniyeh sisters' move to Israel had it applied 30 years ago.
"This is a racist law that makes problems for some people in Israel like the Bedouin who often marry into Palestinian families,'' he said. "It is unfair against us and not against other Israelis.''
Laila and Sabah are both widows but remain in Tel Sheva, apparently reluctant to give up their Israeli citizenship. It is not known when the Haniyeh sisters last had contact with their brother. As he is a Hamas prime minister, contact with him could, under Israeli law, be illegal.