House Republicans investigating the Fast and Furious operation threatened Thursday to seek a contempt of Congress citation against Atty. Gen. Eric H. Holder Jr., saying his Department of Justice has refused to turn over key documents in the Department of Alcohol Tobacco and Firearms gun-tracking investigation and that the Obama administration is trying to hide its involvement in the program that allowed hundreds of U.S. weapons to fall into the hands of Mexican drug cartels.

Rep. Darrell Issa (R-Calif.), chairman of the House Oversight Committee, told Holder in a Capitol Hill hearing that the Justice Department has provided only 6,400 pages of documents out of some 93,000 that they still want — all a sign to him and his GOP colleagues that Holder and top Justice officials in Washington are trying to suppress evidence that they knew about the gun-walking tactics and may have approved Fast and Furious.