For almost forty years, America has been gripped by the desire to finally locate the grave of notorious mob boss Jimmy Hoffa. His life and death are the stuff of legend, and now, new information from a source close to Hoffa may just give investigators the information they need.

An underboss in the Detroit mob, Tony Zerilli, has come forward to say that he is completely certain that he knows where Hoffa's body is located, and that he's been working with authorities so that they can uncover the remains. It may be the most credible lead in the case to date, and has again brought investigators to the state of Michigan.

"According to Zerilli and his description of the property, this seems to be it," said Andrew Arena, who was head of the FBI in Detroit until 2012. "I still don't know if this was a guess on his part. I don't know if he was actually brought here by the Detroit (mob) family. It's his position as the reputed underboss. That's the significance."

Jimmy Hoffa was the head of the Teamsters Union from 1957 to 1971 and had many close ties to Italian mobsters. He was an adversary of public officials and for many years worked just under the radar to help the mobsters accomplish a wide array of illicit activities.

Then one day in 1975, he suddenly disappeared and was never heard from again. Hoffa was supposed to be having lunch with two mob members that day, and the general consensus is that he must have done something to warrant his murder.

"... I think that the crime itself has taken on an unbelievable amount of legs to ... keep the story in the headlines for 35 years-plus," said mob expert Scott Bernstein. "It's a giant black eye for the FBI. It's a piece of local folklore that will always ... beg the attention that it gets. And I think in that regard, you know, it speaks for itself."

Still, the search for Hoffa's body has been completely fruitless thus far. Investigators have followed lead after lead in an attempt to better understand what happened during Hoffa's final hours, and have scoured the state of Michigan to do so. Locating his corpse would finally bring some closure to one of the most pervasive stories in American lore.

"I've been through this so many times. We've been down this trail, this dead-end street -- I can almost think of a dozen separate times," says the prosecutor at the time of Hoffa's disappearance, L. Brooks Patterson. "We sent out the backhoes and tore up property, tore down barns or what have you, and ... I don't care how good the tip is in this instance. I am really pretty much a pessimist on this one,"

Investigators are now searching in Oakland Township, which is about 25 miles north of Detroit. Zerilli has claimed that the body was dumped in a field there, and based on his description of the location, authorities now believe that they have found the location and have already gotten a search warrant to start digging.