"I can't imagine this going anywhere," Dan Moldea, author of the book "The Hoffa Wars," told ABC News in an interview Thursday afternoon.
According to Moldea, the person who triggered this week's search in Michigan contacted him as far back as March 30. The informant, Moldea said, is a gambler who worked with a bookmaker who had ties to Tony Giacalone, the Detroit mafia captain Hoffa was supposed to meet at a Michigan restaurant the day he disappeared in 1975.
When Moldea first heard the tipster's story, "It intrigued me that there was this Giacalone connection." However, Moldea's intrigue quickly turned to skepticism for two main reasons: one, the visibility of the driveway, and, two, the people involved in the informant's tale.
"It is in this little neighborhood where anything that was being done could be seen by everyone," Moldea said. "There was no privacy."
In addition, Moldea warned, "the cast of characters" in the tipster's story just does not add up.
"Why would Tony Giacalone entrust this guy -- a non-made associate -- with this treasure, this trophy, when this guy could blackmail Tony for the rest of his life?" Moldea said. "Plus, whoever has this trophy has the ticket to life imprisonment? Why would you keep the body? You would burn it, chop it up, throw it in the water. You don't take it to a driveway. You don't take it to the Meadowlands. There are plenty of other places right there in Detroit where you can put the body."
"The story didn't make sense," he said. "The key characters we know were involved with Hoffa's disappearance and murder were nowhere to be seen in this."
When Moldea voiced his skepticism to the tipster, the informant "really got mad," Moldea said.
"He really believes that this is where Hoffa is, and so I told him, 'I've heard these things dozens of times in the past 37 years. I've been on this since day one.' I tell all of them go to the FBI because in my mind ultimately, if this case is going to be solved, it's going to be solved by the FBI," Moldea said.
But when the informant went to the FBI, according to Moldea, he "didn't get respect" from them either. That prompted more phone calls to Moldea, an author based in Washington, D.C.. Finally Moldea suggested that the tipster reach out to local law enforcement in Roseville, a town about 20 miles north of Detroit. Roseville police responded to the tipster's request, sending out a team from Michigan's Department of Environmental Quality to conduct a ground scan of the driveway last week that did in fact discover "anomalies" underground.
"Our staff weren't told what or who they were looking for. What they knew was they were down there to do a scan," Brad Wurfel, the spokesman for Michigan's Department of Environmental Quality, told ABC News Wednesday. "What they came up with was some anomalies relatively close to the service."
Still, Moldea remains skeptical that Friday's drilling will lead to Hoffa, who served as president of the powerful International Brotherhood of Teamsters union from 1958 to 1971.
"I've got a Diet Coke in front of me and I wouldn't bet this can that Hoffa is there," he said.
According to Moldea, the tipster is "not a con man" but he is "looking for a reward" if Hoffa's body is found there. When the two last spoke earlier this week, Moldea said the informant was "scared to death" because the bookmaker he worked with -- the one with connections to Giacalone -- is still alive.
"If by some one percent of one percent of one percent chance this guy has actually pinpointed where Hoffa is buried -- which I really doubt -- he deserves any reward he can grab," Moldea said.
But there is one reason Moldea thinks maybe -- just maybe -- this tipster may be on to something.
"This thing is going to come from left field. Someone who wasn't involved in the murder -- their info is going to break this case. And this guy fits that bill," Moldea said. "I'd be shocked if this was it, but I would be so happy because it would get idiots like me -- who've been on this thing for 37 years -- a little vindication."
The search is set for Friday morning. A spokesman for the Teamsters union said the Hoffa family had no comment on the matter.
"The Hoffa family does not respond every time a tip is received by authorities," the union said in a statement. "The FBI keeps the family informed and they will have no comment until there is a reason to comment."
The Roseville Police Department did not respond Thursday to numerous calls and messages from ABC News.