Investigators at the General Accounting Office are quietly skeptical about whether the Air Force told the truth when responding to a controversial request for information by a member of Congress in 1993. So far, however, investigators are not planning to voice their concerns in public, or in a report to be released soon.

At issue are events that took place nearly half a century ago in Roswell, N.M. -- the so-called Roswell Incident -- and whether the Air Force has told the truth about what it knows. Over the years, the Roswell Incident has become a cornerstone of UFO myth, chronicled frequently on television and in at least four books.

It all began in July 1947, when a rancher northwest of Roswell found debris from a crashed object he thought was a flying saucer. Aluminum foil-like bits and pieces were reported to be impervious to burning or ripping, and returned to their original shape after crumpling.

When the then-Army Air Corps investigated, the first official press release issued by local officers declared the military had found remnants of a flying saucer. Within hours, however, higher-ups declared the first press release a mistake and explained that the debris was merely a downed weather balloon.

The story died for decades until the late 1970s, when television picked up on the story. Consistent denials by the Air Force -- and the disappearance of related documents -- only added fuel for the conspiracy theorists.

The issue finally made it to Capitol Hill when a UFO skeptic, Rep. Steven Schiff (R-N.M.), decided to get to the bottom of things. In March 1993 he asked the Air Force to declassify and provide him with all material relating to the incident. But rather than search through their records, Air Force officials referred Schiff to the National Archives -- a move that Schiff took as an insult. The archives promptly told Schiff it had no information.

"Typically, the Pentagon is eager to comply with congressional requests for information," a Schiff spokesman told us. "Yet they just shunted us off to the archives." Seven months later, Schiff called in the GAO (the investigative arm of Congress) to look for documents and to find out if the Air Force lied to him.

Once the GAO launched its inquiry, Air Force officials suddenly found documents -- not in the National Archives, but in their files. They issued a short report last September claiming the debris was part of Project Mogul, an experiment aimed at detecting future Soviet nuclear blasts by monitoring sound waves in the high atmosphere using airborne balloons and sensors. At the time of the Roswell Incident, however, the Soviets were still two years away from building their first nuclear bomb.

Although the GAO is not satisfied with the Air Force's explanation, it has confirmed the existence of Project Mogul. GAO officials add emphatically that no one involved in the audit believes the Air Force is covering up a UFO incident.

"But we do believe that something did happen at Roswell," said one source close to the investigation. "Something big. We don't know if it was a plane that crashed with a nuclear device on it . . . or if it was some other experimental situation. But everything we've seen so far points to an attempt on the part of the Air Force to lead anybody that looks at this down another track."

Enough things were happening around Roswell in 1947 to give the public a mistaken impression that UFOs were landing. Roswell was the home of the 509th Bomb Group, the atomic weapons unit that bombed Hiroshima and Nagasaki two years earlier. Not far away was Alamogordo and the Trinity Site, where the first atomic bomb was exploded. White Sands Missile Range had begun its top secret tests as well.

The Air Force predicts it will get a clean bill of health from the GAO. A GAO spokesman angrily predicted we would be "embarrassed" if we suggested its soon-to-be-issued report was slated to be accusatory.

Another GAO source took a different tack: "What we have found so far is that the Air Force has not told Schiff the whole truth. But we aren't pursuing the truth, either. All our auditors have done is verify that some of the information that was given to Mr. Schiff was very wrong. But we may not call it that way in the end, depending on the way you look at it."

While our sources say the Air Force has been less than forthcoming, the GAO may not make the case in its upcoming report -- especially since it might imply that the GAO believes a UFO landed at Roswell. "We will tend to err on the side of not fueling UFO theories," one GAO official explained.