A top Republican senator slammed the Justice Department for reportedly promoting the supervisors of the failed anti-gunrunning sting operation Fast and Furious, which is under a federal and congressional investigation after weapons linked to program were used in a December attack in Mexico that killed a U.S. border patrol agent.

The Los Angeles Times reported Tuesday that the Bureau of Alcohol, Tobacco, Firearms and Explosives promoted three key supervisors of Operation Fast and Furious who came under fire for pushing the program even after it clearly spiraled out of control.

The three supervisors -- William Newell and David Voth, both field supervisors who managed the program out of the agency’s Phoenix office, and William McMahon, who was the ATF’s deputy director of operations in the West -- are being transferred to Washington for new management positions at the agency’s headquarters, the newspaper reported.

“Until Attorney General (Eric) Holder and Justice Department officials come clean on all alleged gun-walking operations, including a detailed response to allegations of a Texas-based scheme, it is inconceivable to reward those who spearheaded this disastrous operation with cushy desks in Washington,” said Sen. John Cornyn, R-Texas, a member of the Senate Judiciary Committee.

Cornyn sent a letter to Holder last week demanding answers following reports of alleged Texas-based “gun-walking” programs similar to “Fast and Furious.”

Holder insists that he didn’t know about the operation as it was being carried out. But Republican leaders say he should have known.

Spokesmen for the ATF did not return phone calls to the newspaper seeking comment.

At a congressional hearing in June, three ATF agents said they were repeatedly ordered to step aside while gun buyers in Arizona walked away with AK-47s and other high-powered weaponry headed for Mexican drug cartels. So far, 20 small-time gun-buyers have been indicted, but the investigation is still under way.

ATF Acting Director Kenneth Melson admitted last month to congressional investigators that his agency, in at least one instance, allowed sales of high-powered weapons without intercepting them -- and he accuses his superiors at the Justice Department of stonewalling Congress to protect political appointees in the scandal over those decisions.

The operation was designed to track small-time gun buyers up to major weapons traffickers along the U.S. border with Mexico. Critics estimate that 1,800 guns targeted in the operation are unaccounted for, and about two-thirds of those probably are in Mexico.