The Pentagon has barred a pair of intelligence operatives from testifying before a Senate committee about a military operation that allegedly identified a major figure in the 9-11 attacks before they occurred.

Lt. Col. Anthony Shaffer and civilian contractor James Smith were not allowed to answer questions posed by members of the Senate Intelligence Committee regarding “Able Danger,” a secret data-mining operation that allegedly named Mohammad Atta as an al-Qaida operative a year before Sept. 11, 2001.

Both men, who were members of the team, were accompanied by their lawyer, Mark Zaid. The attorney told panel members he had been sent letters by the Defense Intelligence Agency, or DIA, and the Pentagon’s general counsel’s office which expressly forbid Shaffer from providing testimony, Agence France Presse reported.

When pressed on the issue, Defense Secretary Donald Rumsfeld said the Pentagon had offered to provide members a classified briefing on the project behind closed doors.

“And as I understand it, the Judiciary Committee preferred to have an open hearing on a classified matter, and therefore the department declined to participate in an open hearing on a classified matter,” Rumsfeld said.

Able Danger was a small, highly classified operation reportedly created at the behest of then-Chairman of the Joint Chiefs of Staff Gen. Hugh Shelton in 1999 to develop a campaign against international terrorism and, in particular, al Qaida.

According to reports, the Able Danger team had identified Atta, the lead attacker, and three others as probable members of an al-Qaida cell operating in the U.S. by mid-2000. That assertion, however, contradicts earlier government denials U.S. agencies had any prior knowledge of Atta or any others eventually associated with the attacks.

The disclosure of the operation and its alleged findings was first made by Rep. Curt Weldon, R-Pa., in a special orders speech on the House floor, and in his new book, “Countdown to Terror.”

Weldon also has said the information on the prior identification of Atta was provided to the official “9-11 Commission” investigating the attacks, but commission members Timothy J. Roemer and John F. Lehman have said they never received it. He also says when the hijacker team leader was first identified, Pentagon lawyers prevented the passage of the information to the FBI.

A subsequent report by Time magazine said Weldon, in his book, recounted an incident in which he handed then-Deputy National Security Adviser Steve Hadley, just after Sept. 11, a chart produced by the Able Danger team identifying Atta.

But Time said when it interviewed Weldon, he no longer was sure Atta’s name was actually on the chart.

Zaid told senators seeking answers about the operation that the DIA had destroyed charts Shaffer had in his office as late as spring 2004.

“I don’t understand why they would have destroyed any documents, particularly if they were classified, and there was classified information within these boxes,” he said. “The DIA should be required to explain who destroyed the documents and why the destroyed them.”

The Pentagon has tried to downplay any controversy, saying it could find nothing produced by the half-dozen Able Danger team members mentioning Atta by name.

That, however, does not excuse the Defense Department’s reluctance to discuss the issue in the open, charge some lawmakers.

“I think the Department of Defense owes the American people an explanation about what went on here,” Sen. Arlen Specter, R-Pa., chairman of the Senate Judiciary Committee, said. “The American people are entitled to some answers.”

A total of five people were forbidden by the Pentagon to testify on Wednesday, Fox News reported.

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