Report: Whistle-Blower to Testify Against NSA

A former official at the supersecret National Security Agency is reportedly prepared to tell Congress what really went on in the domestic-spying program that was revealed last month.

The Washington Times reported today that Russ Tice, who was fired from the NSA last year, has written and told House and Senate intelligence committees that he knows the government undertook electronic surveillance without obtaining permission from a special secret court.

In letters to the committee, Tice said that "I intend to report to Congress probable unlawful and unconstitutional acts conducted while I was an intelligence officer with the National Security Agency and with the Defense Intelligence Agency."

President Bush, while acknowledging that the special eavesdropping program exists, said it is needed to track down international terrorists through phone numbers linked to al Qaeda. Vice President Dick Cheney said on Wednesday that if the program had been in place before the Sept. 11 attacks, the plane assault on the Pentagon might have been avoided. The Justice Department said that after the 9/11 attacks, Congress granted special powers to the president who then "legally" ordered the spying on communications coming into and out of the United States.

The eavesdropping was first reported by The New York Times. The Justice Department has launched an investigation into who revealed the operation to the newspaper. In his Dec. 16 letters to Congress, Tice said that under a 1998 whistle-blower protection law, he can testify legally about intelligence operations without facing punishment.

The New York Times story came on the same day that Tice sent the letters to the intelligence committee chairmen. Congress is expected to hold hearings soon on whether the eavesdropping violated the right to privacy.

ABC News' John Cochran contributed to this report.