Some of Osama bin Laden's bodyguards have been captured and are among the prisoners at the US military base in Cuba.
Officials say they were assigned to personally protect bin Laden.
But how much information about bin Laden they can, or will, give to US authorities remains unclear.
The bodyguards are among 564 suspected Taliban or al Qaeda members being held at the US Navy base at Guantanamo Bay.
Most of the detainees were captured in Afghanistan or Pakistan during the US-led campaign which began last October.
Military officials say they do not know how many members of bin Laden's security detail are detainees or when and where they were captured.
A senior US official says the bodyguards have been in custody since February.
He says some of them have served bin Laden for years and have travelled extensively with the al-Qaida leader in Afghanistan.
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 physically to bin Laden, their job was to provide muscle, not advice.
PA