Washington ? A Pentagon employee was ordered to destroy documents that identified Mohamed Atta as a terrorist two years before the 2001 attacks, a congressman said Thursday.

The employee is prepared to testify next week before the Senate Judiciary Committee and was expected to name the person who ordered him to destroy the large volume of documents, said Rep. Curt Weldon, R-Pa.

Weldon declined to name the employee, citing confidentiality matters. Weldon described the documents as “2.5 terabytes” – as much as one-fourth of all the printed materials in the Library of Congress, he said.

A Senate Judiciary Committee aide said the witnesses for Wednesday’s hearing had not been finalized and could not confirm Weldon’s comments.

Weldon has said that Atta, the mastermind of the 9-11 attacks and three other hijackers were identified in 1999 by a classified military intelligence unit known as “Able Danger,” which determined they could be members of an al-Qaida cell.