"When the AP got it and started talking about it, it caused all kinds of problems with the operation," said a U.S. official who would not be quoted by name discussing the classified operation. "The investigation never went to its full conclusion."
AP spokesman Paul Colford said the news agency held off publishing until U.S. officials told the AP that security concerns were allayed.
"We were told on Monday that the operation was complete and that the White House was planning to announce it Tuesday," he said.
The disclosure that a double agent had infiltrated an Al Qaeda bomb cell in Yemen, which was first reported by ABC News, could endanger future counter-terrorism operations, U.S. officials said.
"This really puts us in a tough place operationally," said another official not authorized to speak publicly about intelligence matters.
It's not clear whether airport body imaging machines now in use would have detected the latest bomb, said Rep. Adam B. Schiff (D-Burbank), a member of the House Intelligence Committee.
"This was a very big success story that involved a lot of hard work and a lot of skill and some luck," he said. "It's the part that luck plays that concerns me, because we can't always count on luck."