The Sept. 11 commission failed to pursue information that a secret military unit had identified two cells involved in the 2001 terrorist strikes more than a year before the attacks, an Army intelligence officer contends.
Lt. Col. Anthony Shaffer said that in January 2004, the commission declined to take up his offer of assistance.
"I just walked away shocked that they would kind of change their mind, but I figured someone with equal or better knowledge ... probably came and talked to them, so they must've taken care of it," Shaffer told The Associated Press in an interview Wednesday.
The information Shaffer said he gave during a 2003 meeting in Afghanistan was that the unit - known as "Able Danger" - had identified Sept. 11 ringleader Mohamed Atta and three other hijackers as terrorist suspects.
The commission has denied that Atta's name or the name of any future hijackers were mentioned during the meeting, reports Guardian Unlimited.
According to Washigtonpost a statement Friday by former commission chairman Thomas Kean and vice chairman Lee Hamilton said the commission did not obtain enough information on the operation to consider it historically significant.
Shaffer said Able Danger identified Atta and three other Sept. 11 hijackers in 2000. But, he said, military lawyers stopped the unit from sharing the information with the FBI out of concerns about the legality of gathering and sharing information on people in the U.S.
"The lawyers' view was to leave them alone, they had the same basic rights as a U.S. citizen, a U.S. person and therefore the data was kind of left alone," Shaffer said.