The FBI announced today that the search for the body of Jimmy Hoffa, who vanished nearly 38 years ago, has now been called off, as investigators found no remains of the former Teamsters boss in a field in eastern Michigan.

Investigators acting on a tip from a reputed underboss of the Detroit Mafia started digging in a field in Oakland Township, 25 miles north of Detroit, on Monday, after a search warrant was issued in the case. The search area, according to ABC's Detroit affiliate WXYZ, was near land that was once owned by suspected mobsters.

Oakland County Sheriff Michael Bouchard said that although animal bones had been found at the scene, no human remains had been found, WXYZ reported. No physical evidence has been gathered for lab testing, he said.

Authorities search Michigan field for Jimmy Hoffa's body. Read more here.

Tony Zerilli, who the FBI considers a key figure in the Detroit Mafia, told reporter Marc Santia of WNBC in New York that Hoffa was going to be put "in a shallow grave" there and later taken upstate for "final burial" before the plan "fell through."

"The Hoffa body is in that field - no doubt about it," Zerilli's attorney, David Chasnick, said at a news conference Monday afternoon. "There used to be a barn in that field. Buried under the barn, under the cement slab - that's where our understanding is that the body should be."

Hoffa was president of the Teamsters union until 1971. He disappeared from a Detroit-area restaurant on July 30, 1975. He was declared legally dead July 30, 1982.

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