WASHINGTON -- U.S. intelligence agencies are investigating the possibility that the Islamic State of Iraq and Syria (ISIS) militant leader killed Friday was the captor of American hostage Kayla Mueller for a time.
Adam Schiff, the ranking Democrat on the House intelligence committee, confirmed the line of inquiry at a breakfast with reporters Tuesday, but declined further comment. U.S. officials believe Mueller, whose death was announced in February, spent time in the custody of the Tunisian Islamic State finance man known as Abu Sayyaf.
CBS News on Tuesday confirmed Sayyaf's real name was Fathi ben Awn ben Jildi Murad al-Tunisi.
Murad was killed Friday during a rare ground operation in ISIS-held territory in Syria by Delta Force operators. His wife, known as Umm Sayyaf, was taken into custody and is being interrogated, U.S. officials say.
CBS News correspondent Margaret Brennan reports the intelligence recovered has been described as substantial as is the information that the U.S. has gained via interrogation of Sayyaf. She is an Iraqi citizen and is believed to have been an officer herself within ISIS, not just the spouse of the ISIS chief financial officer. The U.S. is very interested in what she knows about ISIS hostages, including but not limited to Mueller.
Intelligence analysts are also sifting through reams of electronic data seized at the site, an official told the AP.
Murad had a number of aliases, the U.S. official said, but officials believe that Murad is his real name. Murad is believed to be the ISIS head of oil operations.
Both officials spoke on condition of anonymity because they were not authorized to discuss the matter publicly.
ISIS said Mueller was killed in a Jordanian air strike, but U.S. officials have cast doubt on that assertion. Mueller and her Syrian boyfriend were taken hostage in August 2013 after leaving a Doctors Without Borders hospital in Aleppo, Syria. The boyfriend was later released.
White House spokeswoman Bernadette Meehan declined to address the issue.
"We are currently debriefing the detainee to obtain intelligence about ISIL operations," she said. "We are also working to determine any information she may have regarding hostages - including American citizens who were held by ISIL."
A U.S. official also provided more details on the Friday night raid.
The commandos who flew by Black Hawk and V-22 Osprey aircraft into Syria under cover of darkness quickly met resistance on the ground. According to Pentagon officials, the U.S. Delta force killed about a dozen militants, Martin reported. There were women and children at the site, but none of them were injured, the officials said. The raid involved some hand-to-hand combat, Martin reported. The ISIS fighters tried to use the women and children in the compound as human shields.
The goal of the mission, which had undergone months of planning, was to take Murad and his wife alive, in the hopes that he would provide intelligence on the group's operations, finances and information on who they do business with and potentially on their leader, Abu Bakr al-Baghdadi. Another part of the plan was to free an 18-year-old girl who is a Yazidi and was believed to have been kept as a slave by the ISIS leader and his wife.
The girl was found and freed by the commandos and is expected to be returned to her family after she is debriefed by the U.S.
A team from U.S. intelligence agencies is poring over the laptops, cellphones, computer drives and other data recovered at the site.