New Search for Jimmy Hoffa's Body
PHOTO: Investigators look over the scene in Oakland Township, Mich., June 17, 2013, where officials search for the remains of Teamsters union president Jimmy Hoffa who disappeared from a Detroit-area restaurant in 1975.

Authorities today were searching a field in Michigan for the body of former Teamsters boss Jimmy Hoffa, the latest in a decades-long string of searches for the missing labor leader who disappeared nearly 38 years ago.

Investigators started digging in a field in Oakland Township after a search warrant was issued in the case. The search area, according to ABC News Detroit affiliate WXYZ, is near land that was once owned by suspected mobsters. Approximately 20 federal agents focused their search Monday morning on one spot in the center of the field.

In January, a reputed underboss of the Detroit mafia said he believed Hoffa was buried in the area. Tony Zerilli, who the FBI considers a key figure in the city's 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."

Zerilli, who was in jail at the time of Hoffa's disappearance, should be taken seriously by authorities, according to Dan Moldea, author of "The Hoffa Wars."

"Zerilli was the underboss of the Detroit mafia. His father, Joe, was the boss of the Detroit mafia at the time Hoffa disappeared," Moldea said in a phone interview with in January. "Therefore, anything that happened in Detroit at that time had to be checked by Joe - so his father clearly knew about what happened with Hoffa. Now Tony was in jail at the time but did he receive some information? I'd say it was very likely, especially once he got out."

Hoffa, who headed the powerful International Brotherhood of Teamsters Union at one point, vanished in July 1975. He was 62 at the time and had recently spent nearly five years behind bars.

In the past few decades, numerous tips have emerged about his whereabouts, only to lead to nothing. Last September, police in Roseville, Mich., about 20 miles north of Detroit, dug up a driveway. In 2009, FBI agents dug up a lumberyard in the city, prompting speculation that the excavation was a search for Hoffa. Three years earlier, in May 2006, a search for Hoffa at a farm in the town of Milford, Mich., was known as "The Big Dig."

Zerilli released a book, "Hoffa Found," earlier this year.

(Carlos Osorio/AP Photo)

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