The investigative arm of Congress says it will review the scientific methods the FBI used when it concluded that Army scientist Bruce Ivins acted alone in the 2001 anthrax mailings.

In a letter to Rep. Rush Holt, D-N.J., the Government Accountability Office says it will look into what scientific concerns and uncertainties, if any, remain in the case.

The GAO also will examine how effective federal agencies are in monitoring high-containment laboratories in the United States and abroad.

The National Academy of Sciences is conducting a separate, independent review due this fall of the scientific approaches the FBI employed in its anthrax probe. The GAO says it will review the academy's work in order to avoid duplication.