Five weeks after Loeb Professor of Biochemistry and Biophysics Don C. Wiley inexplicably vanished in Memphis, police found his body on Dec. 20 in the Mississippi River 320 miles downstream from the city.

The body—carrying a wallet containing Wiley’s identification—was found on a tree near a hydroelectric plant in Vidalia, La. Using Wiley’s dental records, the Shelby County (Tenn.) medical examiner’s office officially determined that it was Wiley’s body Dec. 22, Memphis Police Department spokesperson Latanya Able said.

University President Lawrence H. Summers acknowledged Wiley’s death in a statement, saying his “loss leaves a tremendous void.”

Able said yesterday that the department is still waiting on the results of the autopsy to determine the cause of death and does not know when these results will be available.

The Shelby County medical examiner’s office is conducting the autopsy.

Able said earlier that Memphis police would continue their investigation until they received official word from the medical examiner explaining how Wiley died.

Wiley left a conference at the Peabody Hotel in Memphis around midnight on Nov. 15. 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. “The guy had everything in the world going for him. He had looks, money, prestige, property. What more could you want?”

Baird Professor of Science Andrew McMahon, chair of Wiley’s department, said Wiley was “a vital force” during his 30 years in the department of molecular and cellular biology.

“His combination of energy, boyish enthusiasm and sharp intellect has played a major role in all of our activities,” McMahon said. “His absence leaves a great void.”

The search for Wiley initially attracted national attention because of his work with infectious diseases—a topic of considerable concern after Sept. 11. Despite widespread speculation, his family—as well as Harvard colleagues—said it was unlikely that bio-terrorism had anything to do with his disappearance.

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