(CBS News) The FBI is resuming its hunt for Jimmy Hoffa's body after an ex-mobster led them to the search site in a Detroit suburb.
Agents have so far found animal bones but also a cement slab that reputed Detroit mobster Tony Zerilli said would be there. Zerilli was in prison when Hoffa disappeared, but he insists he knows how Hoffa died and where he's buried.
About an hour north of Detroit, in the rural area of Oakland Township, FBI agents are digging at a site where an old barn used to stand, searching for the remains of the powerful Teamsters leader.
According to 85-year-old mobster Zerilli, Hoffa was buried there, the victim of a hit ordered by a mob boss who was worried that Hoffa would cut off his access to union funds.
Zerilli, speaking to a Detroit TV station on Tuesday, said, "Mr. Hoffa was picked up and taken and buried alive."
In a 22-page manuscript, Zerilli added, "A cement slab of some sort was placed on top of the dirt to make certain he was not going to be discovered. And that was it. End of story."
Hoffa, who allegedly had mob ties, was last seen outside a Detroit-area restaurant in 1975. Since then, his fate has been the subject of rampant speculation.
Some have claimed his body was buried beneath the end zone of the old Giants Stadium or even under the Everglades, and searches throughout the years have turned up nothing.
Zerilli, who was reportedly once the number two in command of Detroit's mafia, says the mythical tales of Hoffa's demise were just that.
In the manuscript, which he is selling online for $4.99, Zerilli wrote: "In the movies, people drive around with bodies in a trunk and put them in meat grinders and incinerators, bury them in stadiums, put them through wood chippers and so on and so forth. Those things just don't happen in real life."
So why is Zerilli coming forward now, after all these years? David Chasnick, Zerilli's lawyer, said, "Mr. Zerilli had a very, very close relationship with Mr. Hoffa. He's 85 years old, it's something that's bothered him for years. He wants to clear his conscience and help out the family. Let the remains be found, and the let the whole deal be put to rest once and for all."
Forensic anthropologists with Michigan State University are on the scene, assisting the FBI. There's no word on how long the search might last.
Watch Elaine Quijano's full report in the player above.