(CBS) Some of al Qaeda leader Osama bin Laden's bodyguards have been in U.S. custody since February at the U.S. Navy base in Guantanamo Bay, Cuba, officials say.

Military officials said Tuesday they didn't know how many of bin Laden's bodyguards were among the 564 suspected Taliban or al Qaeda prisoners held in high-security metal cells at Guantanamo Bay.

But some of the bodyguards have served bin Laden for years and traveled extensively with him in Afghanistan, said a senior U.S. official familiar with the matter, who spoke on condition of anonymity.

How much valuable information the bodyguards could give, assuming they were to decide to talk, remained unclear.

Bin Laden has a reputation for being meticulous about his security, choosing bodyguards for their loyalty and willingness to sacrifice themselves to protect him.

While the detained bodyguards were among those who stayed closest to the al Qaeda leader, their job was to provide muscle, not advice. His bodyguards are not expected to know much about planning for past or future attacks beyond the stray snippets of conversations they may have overheard between bin Laden and his lieutenants, officials said.

They could provide U.S. interrogators with information about bin Laden's movements and security precautions, although bin Laden would be expected to change such things if his bodyguards were captured.

Officials have said one of bin Laden's many sons, Mohammed, is part of his father's security detail. Mohammed bin Laden is not believed to be in custody. U.S. officials also have said another bin Laden son, Saad, is gaining influence as an al Qaeda leader.

Bin Laden's security chief is an Egyptian named Saif al-Adl, who is wanted in connection with al Qaeda's 1998 bombings of two U.S. embassies in Africa. Al-Adl is regarded as a key leader in al Qaeda, and officials have suggested he is capable of running the organization if bin Laden were to be killed.

The fact that some of bin Laden's bodyguards have been captured does not necessarily indicate bin Laden is dead, U.S. officials say. Recent military intelligence reports have not supported that idea, and the military believes bin Laden could be alive, according to a Defense Department official who spoke on condition of anonymity.

Still, bin Laden's last appearance on video was more than seven months ago, and FBI counterterrorism chief Dale Watson said earlier this month he believes bin Laden is dead.

The last time U.S. officials said they had a credible fix on bin Laden's location was in December, when he was believed to be in the Tora Bora region of Afghanistan. He is thought to have fled as America's Afghan allies approached.

U.S. and Canadian experts later exhumed 23 elaborately marked graves in Tora Bora, the rugged Afghan mountain region near the Pakistan border dotted with reinforced caves. Those graves held the bodies of other members of bin Laden's security detail.

Other evidence suggests bin Laden may have jettisoned most of his entourage in favor of just a few highly trusted associates: Published reports said a video found by allied forces in February showed bin Laden camping with just a few other people.

Defense Secretary Donald H. Rumsfeld said last week he did not know if bin Laden was dead or alive.

"I've not heard hide nor hair of him since December," Rumsfeld said. "He's either dead, which is fine from our standpoint, or he's alive and for some reason decides he does not want to live up to his reputation as enjoying going on videos and letting the world know that he's alive."