MARSEILLE, FRANCE

The demise of Antoine de Saint-Exupéry on a reconnaissance mission in World War II has long ranked as one of aviation's great mysteries. Now, thanks to two amateur archaeologists, the final pieces of the puzzle seem to have been filled in.

On July 31, 1944, Saint-Exupéry, the author of several adventure books on flying and the charming tale "The Little Prince," about an interstellar traveler, took off from Corsica in a Lockheed Lightning P-38. He was one of numerous French pilots who assisted the U.S. war effort. Saint-Exupéry never returned, and over the years numerous theories arose: that he had been shot down, lost control of his plane, even committed suicide.

The first clue surfaced in September 1998, when fishermen off this Mediterranean port city dragged up a silver bracelet with their nets. It bore the names of Saint-Exupéry and his New York publisher. Further searches by divers turned up the badly damaged remains of his plane, though the pilot's body was not found.

News of the bracelet prompted Luc Vanrell, 48, a diving coach and marine archaeologist, to inspect more closely some marine wreckage he had noticed years before buried near Saint-Exupéry's plane. An engine block serial number and a Skoda symbol, for the Czech company that was an unwilling German supplier, proved it to be a Daimler-Benz V-12 aircraft engine.

In 2005, after enduring numerous bureaucratic delays, Vanrell and another diver, Lino von Gartzen, lifted the motor and shipped it to Munich for study by German experts. It turned out to be part of a series produced in early 1941. It had been modified in 1943 with the addition of a fuel injection pump. The researchers deduced it had powered a Messerschmitt fighter plane, part of a training unit stationed in southern France from 1942 to 1944.

It had been flown by Prince Alexis von Bentheim und Steinfurt, a 22-year-old who was shot down by U.S. planes in late 1943, on his first and last solo flight.

The tale might have ended there. But Von Gartzen was not content. Consulting archives and enlisting the help of the staff of the Jaegerblatt, a magazine for Luftwaffe veterans, he tracked down pilots who had flown in Von Bentheim's unit.

In July 2006, he telephoned a former pilot in Wiesbaden, Horst Rippert, explaining that he sought information about Saint-Exupéry. Without hesitating, Rippert replied, "You can stop searching. I shot down Saint-Exupéry."

Rippert, who will be 86 in May, worked as a TV sports reporter after the war. It was only days after he had shot down a P-38 with French colors near Marseille that he learned of Saint-Exupéry's disappearance.

He was convinced that he had shot him down, though he confided his conviction only to a diary. In 2003, when he learned that Saint-Exupéry's plane had been located, his suspicion was confirmed. But still, he said nothing publicly.

Over the years, the thought that he might have killed Saint-Exupéry had troubled Rippert. As a youth in the 1930s, he had idolized the aviator-turned-author and had devoured his books, beginning with "Southern Mail," in 1929, an adventure tale written while Saint-Exupéry was flying the Casablanca-to-Dakar route.

Evidence to support Rippert's claim is lacking because documents, like flight logs, were destroyed in the war. But Rippert described in detail to Von Gartzen how, in the summer of 1944, German radar had alerted his fighter squadron at Marignane, near Marseille, to a group of allied reconnaissance planes over the Mediterranean. Rippert, who was then 22, found a P-38 with French colors and shot it down.

He described the odd, evasive loops flown by Saint-Exupéry, who was 44, overweight and in pain from fractures sustained in numerous flying accidents. Several days later, when German radio intercepted American reports of a search for Saint-Exupéry, he suspected that he might have shot down his idol. When Rippert told Von Gartzen of learning that Saint-Exupéry was missing, "he had tears in his eyes," Von Gartzen said.

In Paris, Saint-Exupéry's grandnephew, Olivier d'Agay, a spokesman for the family, said that Rippert's version of the events was credible.

And Von Gartzen remarked: "Rippert said he often felt desperate. If he had known what he was doing, he never would have done it."