U.S. intelligence officials say some top al Qaeda agents have been quietly moving in and out of Iran.

Some of those operatives had been detained for years by Iran, but have been released.

Clare Lopez, a former CIA officer now a senior fellow with the Center for Security Policy, appeared on CBN Newschannel's Morning program for more insight on the issue. Click play to watch the interview.

The Iranian regime and al Qaeda have not typically worked together. But U.S. officials report that there are signs that the Islamic Republic is loosening its hold, allowing al Qaeda to replenish its leadership and ranks.

They said this could foreshadow the release of some of the terror group's most dangerous figures.

If true, that would mean bad news for the War on Terror. Any influx of leadership could hand al Qaeda a boost in morale and expertise and threaten to disrupt stability in the region.

U.S officials admit watching and understanding al Qaeda in Iraq has always been a difficult job.

"This has been a dark, a black zone for us," former CIA officer Bruce Riedel said. "What exactly is the level of al Qaeda activity in Iran has always been a mystery."