The Navy's A-12 stealth aircraft program, already under attack for cost overruns and schedule delays, now is the focus of a criminal probe, the Defense Department says. ``The U.S. attorney for the Eastern District of Missouri presently is conducting and directing a criminal investigation into the overpayment of progress payments,'' the Pentagon's inspector general, Susan Crawford, said Monday. Crawford made the disclosure at a House Armed Services Committee hearing on the attack plane, designed to replace the Navy's aging fleet of A-6 Intruders aboard aircraft carriers starting in 1995. ``Both the Defense Criminal Investigative Service, which works for me, and the Naval Investigative Service are working in a joint fashion under the direction of the U.S. attorney,'' she said. The plane's contractors, McDonnell Douglas Corp. and General Dynamics Corp., are based in St. Louis. The Navy announced last week that it was removing three top overseers of the A-12 program, including two admirals, for failing to disclose serious flaws in the aircraft's development. Five weeks after Defense Secretary Dick Cheney told Congress in April that the program was on track, it was disclosed that the A-12 was 18 months behind schedule and more than $1 billion over the planned $4.7 billion cost. Navy Secretary H. Lawrence Garrett told Cheney last week that he was forcing Vice Adm. Richard C. Gentz, commander of the Naval Air Systems Command, to retire by Feb. 1. Garrett also said he was reassigning Rear Adm. John F. Calvert, the program executive officer for tactical aircraft programs, and Capt. Lawrence S. Elberfeld, A-12 program manager, and writing each a letter of censure. But Garrett said he would not stop Elberfeld's scheduled promotion to rear admiral. Garrett, testifying before the House panel Monday, faced criticism for that decision from Rep. Andy Ireland, R-Fla. ``I wonder what message you send when you include censure and a promotion as well,'' Ireland asked. ``The message is already clear,'' Garrett responded. ``That you can be promoted,'' Ireland interrupted. The Navy secretary argued that the promotion of Elberfeld was based on his 20 years of service and the censure even with the promotion would be ``embarrassing and debilitating'' to Elberfeld's future career. An internal Navy report and the Pentagon inspector general's investigation indicated last week that the government did not sufficiently challenge overly optimistic cost and schedule estimates of the contractors. The Navy report said McDonnell Douglas and General Dynamics contract officials failed to tell the Navy of cost and schedule problems. Garrett testified that briefings from the Navy's management team on the A-12 program ``gave no indication of risk that the contract would not be completed within its ceiling price, nor any risk that first flight and the follow-on test program would not be achieved.'' The Navy secretary blamed ``human errors in judgment'' for problems with the aircraft that were never reported. He added that although the current procurement system works, individuals ``find it very hard to push bad news up to the top.''