On July 14, 1980, the CIA's top official in Rome reportedly hustled over to the office of Gen. Zeno Tascio, the head of Italian air force intelligence, who suggested that a team of U.S. government experts be sent to inspect the wreckage of a Libyan MiG-23 that had crashed in southern Italy. Another plane, an Italian DC-9 commercial jetliner with 81 passengers and crew, also had crashed in the sea in the same region.

The CIA team visited the site of the Libyan crash and removed some of the wreckage before the incident became public, recalled Duane R. "Dewey" Clarridge, then the CIA station chief at the U.S. Embassy. When Italian officials finally announced the Libyan plane crash, they said it occurred on July 18, four days after Clarridge's visit with Tascio--a deception the United States has never challenged.

Over the past two decades, questions surrounding the date and other aspects of that crash and its possible connection to the DC-9 crash have provoked broad speculation in Italy, giving birth to a minor cottage industry of conspiracy theories and at least three official inquiries.

Last month, an independent Italian magistrate issued a 5,000-page report that essentially accuses the U.S. and Italian governments of covering up the circumstances surrounding the crashes. It suggests that NATO military aircraft--most likely American--were in a dogfight with the Libyan MiG over the Tyrrhenian Sea and may have inadvertently caused the crash of the commercial jetliner, which was flying in the same area. The report raises the possibility that an errant missile or the other planes' maneuvers caused the DC-9 to crash.

Justice Rosario Priore, who has investigated the matter for nine years, surmises in his report that the Libyan plane was shot down on June 27, the same date as the DC-9 crash. Priore discounts speculation that the DC-9 might have crashed because of an internal explosion, or "clear air turbulence," as some U.S. government experts initially said.

NATO, American and Italian military officials have repeatedly dismissed any relationship between the two crashes and have described the dogfight theory as a wild conspiracy tale, based on unconfirmed suspicions and chimerical radar data.

But Priore, who has specialized in terrorism matters for the past 34 years, attributes a series of gaps in records of the incident, shifting statements and factual discrepancies to a genuine conspiracy, ruling out faulty memory about the 1980 events.

Although Priore has been unable to determine whose planes may have been involved, his report makes clear that he suspects the United States. The U.S. government, he says, at first said none of its aircraft was flying in the region at the time, then admitted that five of its aircraft were present but claimed they were unarmed.

A U.S. Embassy spokesman in Rome said the United States has bent over backward to reply to 57 requests for information by Priore. But Priore said military secrets were withheld and that in three interrogations, Richard Coe, a former assistant to the Air Force attache at the U.S. Embassy, gave "contradictory, unreliable, and nearly tormented answers."

On Aug. 31, Priore indicted some of Italy's most respected military officers for treason, in effect accusing them of trying to protect U.S. relations with Italy by willfully obstructing his investigation. The indictment attracted considerable attention here, partly because it feeds a long-standing resentment, especially among the Italian left, over the influence of the United States and NATO in Italy.

Among the mysteries cited in Priore's report is a 22-minute gap in NATO radar records the day of the crash and what Priore calls the "more than casual" disappearance or destruction of other potentially important evidence.

The report expresses alarm, for example, that a U.S. aircraft carrier's log of events before and after the DC-9 crash was recopied and that radar tapes from the carrier--then stationed off the Italian coast--were retrieved by U.S. Navy officials before being reused. Similarly, the French government failed to provide even a "minimal" reply to some of Priore's questions and evidently also recopied critical naval logbooks, the judge complains.

Priore's report surmises that one of the motivations for the coverup was U.S. and Italian embarrassment over their differences about policy toward Libya and its leader, Moammar Gadhafi. At the time of the crash, the Italians continued to support private investment in the North African country despite the U.S.-backed Western embargo imposed in 1978.

A key sign of Italy's cozy relationship with Libya was its willingness to allow a private firm in Venice to outfit at least eight Libyan C-130 transport planes for military use at a cost of $11.3 million each in 1979 and 1980. The refurbishment, conducted by Officine Aeronavali di Venezia, a firm that also serviced Italian military and intelligence aircraft, violated the embargo, Priore reports.

A U.S. supplier of the Italian company, based in Chicago, was ultimately fined $4.3 million in federal court, but no similar action was taken by the authorities in Rome. Instead, the Italian government let Libyan pilots fly the refurbished planes from Venice to Libya. Two of the C-130 planes were slated to have been moved in mid- to late-June, around the time of the DC-9 crash, but the paperwork documenting the flights disappeared.

Priore suspects that the MiG may have been escorting one of the refurbished Libyan C-130s as it traveled south along the Italian coast toward Tripoli, the Libyan capital. The C-130, he says, in turn may have been using the DC-9's flight from Bologna to Palermo as a sort of radar cover--flying close enough so its radar echo merged with that of the civilian aircraft.

According to the logic of this theory, NATO jets may have been tracking the Libyan C-130 and its MiG escort as they traveled through Italian airspace.

The Italian and U.S. governments have long said that no other aircraft were in the vicinity of the DC-9 at the time of the crash. But Priore cites past testimony from two American experts--John Macidull, a crash investigator at the National Transportation Safety Board, and John Transue, a civilian official at the Pentagon--who confirmed that signals picked up by a NATO radar in the coastal city of Masala indicate the presence of at least one aircraft flying near the DC-9. Two other radar stations noted traces of three aircraft that merged when the DC-9 passed over Tuscany, in central Italy, according to the report.

Shortly before the crash, an unidentified aircraft traveling alongside the DC-9 accelerated and turned toward it--possibly to aim a missile--and the commercial jet promptly plummeted into the sea, the U.S. experts told Priore. Macidull, now retired, says the information is consistent with a mistaken attack on the passenger jet.

Clarridge, who now works for a defense firm in San Diego, says he suspects the plane was shot down by Israel, which wanted to stop a scheduled flight of nuclear fuel from France to Iraq along the Italian coastline that day and attacked the DC-9 in error. Priore says that French, Iraqi and International Atomic Energy Agency officials all refused comment on such a flight.

The MiG crashed on a Calabrian mountainside just a few minutes' flying time from where the DC-9 went down.

Just how--and why--the MiG was flying over Italy remains unclear. Libya said the plane had traveled off course when it was put on autopilot during a training exercise in Libyan airspace. After visiting the MiG-23 crash site, the CIA concluded that the pilot was attempting to defect and ran out of fuel, Clarridge told Priore. But Priore said the jet did not have enough fuel to reach the area from Libya and that he has American photographs displaying machine-gun bullet holes in the fuselage.