Five weeks after Harvard biochemistry professor Don C. Wiley inexplicably vanished in Memphis, police have found his body in the Mississippi River 320 miles downstream from the city.

The body--carrying a wallet containing Wiley's indentification--was found on a tree near a hydroelectric plant in Vidalia, La., Thursday morning. According to Memphis police spokesperson Latanya Able, the New Orleans branch of the Federal Bureau of Investigation promptly contacted Memphis officials that afternoon, and the body was transported to Memphis for autopsy Thursday night.

Using Wiley's dental records, the Shelby County (Tenn.) medical examiner's office officially determined today that the body found in the river was Wiley's body according to an interview with Memphis police Lt. Walter Norris conducted by the Associated Press. However, the medical examiner's office has not yet determined the cause of Wiley's death.

Able said that Memphis police would continue their investigation until they received official word from the medical examiner explaining how Wiley died. Wiley's brother Greg Wiley said that a ruling was not expected for two weeks.

Wiley left a conference at the Peabody Hotel in Memphis around midnight on Nov. 14. His abandoned rental car was found on a bridge over the Mississippi River four hours later, with a hubcap missing and streaks of yellow paint on the bumper.

Wiley's disappearance mystified both investigators, who initially regarded it as a probable suicide, and close relatives, who insist that the professor was at the pinnacle of his career.

"It is inconceivable to me that my brother committed suicide," Greg Wiley said yesterday. "The guy had everything in the world going for him. He had looks, money, prestige, property. What more could you want?"

University President Lawrence H. Summers acknowledged Wiley's death in a statement Thursday night, saying his "loss leaves a tremendous void." Wiley's wife, Katrin Valgeirsdottir, is in Iceland and could not be reached for comment.

--Material from the Associated Press was used in the writing of this story

--Staff writer Daniel K. Rosenheck can be reached at rosenhec@fas.harvard.edu