Osama bin Laden's death will likely cripple al-Qaida's fundraising efforts, former undersecretary of Terrorism and Financial Intelligence for the U.S. Treasury, Stuart Levey, told Marketplace Radio, Monday.

"His death will be a very significant blow to al-Qaida's ability to raise money around the world," said Levey, "both in terms of inspiration, but also interestingly in terms of authentication."

One challenge for al-Qaida fundraisers is convincing donors that they are actually true representatives of bin Laden and the al-Qaida movement, Levey explained. "With the loss of bin Laden I think that sort of fundraising will become more difficult and complicated," he said.

Levey also pointed out that al-Qaida lost its chief financial officer and the group's suspected third-in- command, Mustafa Abu al-Yazid a.k.a. Sheik Saeed al-Masri, in May 2010.

"Wealthy donors gave their money and, more important, placed their trust in Yazid," Levey wrote at the time. That, he continued, "makes him exceedingly difficult to replace."

Others replaced Yazid, said Levey, "but we don't know that they exerted the same control."

Now, with bin Laden gone, the authentication problem is doubled. "The combined loss of Sheikh Saeed with the loss of bin Laden could be tremendously painful to al-Qaida from a financial perspective," said Levey.

In addition, documents recovered by U.S. forces from bin Laden's Abbottabad compound could help choke off the flow of funds to al-Qaida. Some of those documents, ABC News reports, might hold the names of some of al-Qaida's biggest donors. "If people have been giving money, and they don't know yet whether their name is being identified in this intelligence, or that their name might be on a list of potential donors, they might have real reason to worry," Levey said.