Claims by the son of a Hamas founder Wednesday that he was a long-term spy for Israel exposed a new side of the Islamic militant group's vulnerability and punched a hole in its meticulously groomed image of secrecy and discipline.
The spy affair comes at a time when Hamas is still reeling from suspicions that Hamas informants helped Israel assassinate a top Hamas operative in a Dubai hotel. The back-to-back scandals were sure to leave Hamas leaders fearful of their own and ever more painfully aware of how capable Israel is of reaching the inner circles of their organization.
At the center of the latest affair is 32-year-old Mosab Yousef, a son of Sheik Hassan Yousef, a Hamas founder serving a six-year term in an Israeli prison.
Hamas, which overran the Gaza Strip in 2007, dismissed the younger Yousef's claims as a lie and said they were part of an Israeli attempt to weaken the movement. However, the man's father did not rule out that his son was an informer, contending he was blackmailed by Israeli agents as a teen.
Analysts said the disclosures hurt Hamas' image and were sure to trigger new security concerns in the movement.
The Israeli Haaretz daily reported Wednesday that Mosab Yousef provided intelligence to Israel's Shin Bet security service for more than a decade, preventing dozens of Hamas attacks against Israelis, including suicide bombings, saving hundreds of lives. The paper said he also helped put several senior Palestinian operatives behind bars.
The younger Yousef, who moved to California in 2007, declined an interview request by The Associated Press.
His memoir, "Son of Hamas," is being published in the United States next week. His publicist confirmed that the information presented by Haaretz is described in the book. The author wrote on his Facebook page that his memoir "will blow your minds away, it is going to be like a tsunami in the Middle East."
Mosab Yousef was considered one of the Shin Bet's most valuable assets and was dubbed "The Green Prince," a reference to his Hamas pedigree and the Islamists' signature green color, Haaretz said.
The newspaper said it confirmed Mosab Yousef's account with Shin Bet agents, including his handler. The report said Mosab, who converted to Christianity, despised Hamas and acted out of ideological conviction.
The elder Yousef said in a statement from prison that he did not rule out that his son was recruited by Israeli intelligence, but he had no access to the movement's secrets.
The father said Mosab was first blackmailed by the Israeli agents as a 17-year-old, and others in Hamas were told. The cleric did not say what damaging information Shin Bet might have used against his son.
"Whether what Haaretz reported is true or not, Mosab was not an active member in Hamas or in any of its military, political or religious branches, or any other body," the elder Yousef said in the statement distributed by Hamas.
Mosab Yousef was first jailed by Israel in 1996 and released in 1997.
The Shin Bet routinely tries to recruit Palestinians of all factions as informers, including those in prisons, by using blackmail or promising benefits, such as work or travel permits.
The spy affair comes at a time when Hamas is still smarting from the Jan. 19 assassination in Dubai of Mahmoud al-Mabhouh, suspected by Israel of procuring Iranian arms for Gaza.
On Wednesday, Dubai police said at least 15 more suspects using foreign passports are wanted for the slaying of the Hamas commander, raising the alleged hit squad tally to at least 26. Several names were traced to Israeli dual nationals, but all denied involvement.
The violent Hamas has been in Israel's sights since its founding in 1987. Israel has killed key Hamas leaders in Gaza, most in airstrikes, though it botched a 1997 attempt to kill Khaled Mashaal, now the movement's supreme leader.
Authorities in Dubai have arrested two Palestinians in the al-Mabhouh slaying. Hamas' Fatah rivals in the West Bank have alleged that Hamas moles helped the killers.
Hamas officials have countered that the Syria-based al-Mabhouh was careless, booking his trip through the Internet and informing his Gaza family of the name of the Dubai hotel where he planned to stay. The family denied al-Mabhouh gave them information.
Hamas also denied media reports that two al-Mabhouh aides in Damascus were sought for questioning about the assassination. Instead, Hamas has alleged that the two Palestinians in custody in Dubai had links to Fatah.
Hamas long prided itself in its secrecy and discipline, in contrast to the fractious, unruly Fatah movement.
However, analysts said that as Hamas grew from a shadowy underground movement into Gaza's ruler, it became more vulnerable to infiltration.
"Hamas is no longer a small organization which is easily controlled by any leadership," said Khaled Hroub, a Hamas expert at Cambridge University.
The al-Mabhouh assassination undermined Hamas' image as a coherent, organized group, and the exposure of Mosab Yousef as an informer was even more damaging, he added.
"There have been a number of stories of having some collaborators on the margins and fringes (of Hamas), but not the son of a leader," he said. "It will leave a stain on Hamas' image."