WASHINGTON — When Mohamedou Ould Slahi's name appeared on the list released last week of Guantanamo Bay detainees, the Pentagon was officially confirming that one of Al Qaeda's most mysterious figures had been in custody since late 2001.
And recently declassified documents show that Slahi has been talking to interrogators the whole time.
But the documents also show that the puzzle of a man U.S. terrorism experts believe was involved in the Sept. 11 attacks and the millennium plot to bomb Los Angeles International Airport seems only to grow deeper.
Slahi has maintained his innocence and said he's such a valuable intelligence asset that his captors should set him free to live in the United States -- with the government providing security.
"Slahi was always a mystery man within the Al Qaeda hierarchy," said Roger W. Cressey, a senior White House counter-terrorism official from 1999 to 2001 who investigated Al Qaeda plots.
"We could never prove he was the one who activated the Montreal [millennium] cell, but he had enough ties and relationship and dealings with known Al Qaeda operatives that would lead one to question his claims of innocence."
U.S. officials say they think Slahi was a major conduit between Al Qaeda cells in Europe and Canada and its home base in Afghanistan. And there is evidence suggesting that he established small businesses to camouflage movement of money and militants.
As such, authorities believe Slahi, 34, holds valuable clues to how Al Qaeda operates. They say he might prove extremely helpful in unraveling tendrils of the terrorist network that still exist.
And authorities say he may know the identities and whereabouts of others involved in the Sept. 11 attacks and the plot to bomb LAX around New Year's Eve in 1999.
But Slahi is not among the 10 or so suspected Al Qaeda operatives at the military prison in Cuba who have been sent before military commissions for trial.
"They say all these bad things about him," Nancy Hollander, Slahi's attorney, said Friday. "The bottom line is, if he's such a bad dude, why aren't they bringing him to a commission? If they've got something on him, charge him and let us defend this case."
Slahi is appealing his designation as an "enemy combatant." His name was among the detainees whose identities were released Wednesday under the Freedom of Information Act as having passed through the Combatant Status Review Tribunal process in 2004 and 2005.
