Mosab Hassan Yousef now lives in exile in California. The 32-year-old Palestinian convert to Christianity escaped his native West Bank in 2007. He has good reason to never return. Next week his memoir "Son of Hamas," will be published in the U.S., revealing his years as one of Israel's most valued informants inside Hamas.
He is the son of Sheikh Hassan Yousef, one of the Islamic movement's founders and who is currently in an Israeli prison. According to an interview Mosab gave to Israel's Haaretz newspaper, his work with the Shin Bet, the Israeli domestic spy agency, saved dozens of Israeli lives from thwarted Hamas attacks.
The revelation that someone so close to the leadership of Hamas was working hand in glove with Israel's security forces will shock Palestinians and Israelis alike.
Yousef, 32, was considered Israel's best placed collaborator inside the organization whose violent attacks have claimed hundreds of lives.
He was given the operational code name Green Prince, a play on Hamas's green flag and his father's prominence in the movement.
According to one of his former Israeli handlers quoted in the forthcoming book, Yousef collaborated with Israel because he wanted to save lives.
"The amazing thing is that none of his actions were done for money. So many people owe him their life and don't even know it," said the handler known only as Captain Loai. "People who did a lot less were awarded the Israel Security Prize. He certainly deserves it."
In addition to providing warning of imminent suicide attacks, the book claims he also helped Israel arrest many high-level Palestinian suspects during the second Palestinian uprising or Intifada. They included Ibrahim Hamid, a senior Hamas commander, Marwan Barghouti, the popular leader of the Fatah party, and Abdullah Barghouti, one of Hamas's most prolific bomb makers. All are now serving multiple life sentences in Israeli prisons.
According to Yousef's memoir his decision to start working for Israel came when he was arrested and detained in 1996. He cut a deal to work with the Israeli internal security agency Shin Bet and was released in 1997.
In a telephone interview with Haaretz from his Californian home Yousef said: "I wish I were in Gaza now. I would put on an army uniform and join Israel's special forces."
He says his book is designed as a message of peace to Israelis, but he has little hope that a peace agreement will emerge any time soon.
"Hamas cannot make peace with the Israelis," he said. "That is against what their God tells them. It is impossible to make peace with infidels, only a ceasefire."
In Israel's long war against Palestinian militants it has always recruited Palestinian collaborators. Often they are induced to work in return for cash or other favors for themselves and their families.
They lead a precarious life inside the occupied territories and if exposed are often summarily executed. The lucky ones are relocated by Israel and given new identities.
Hamas leaders are still reeling from the recent assassination of Mahmoud al Mabhouh in his Dubai hotel room last month. Israel is widely thought to have carried out the killing but refuses to confirm it.
Dubai police suspect the Israelis had help from Palestinian collaborators including a source inside Hamas. Two Palestinians with links to the rival Palestinian faction Fatah have already been detained.