Authorities drilled through concrete and removed wet soil samples in a modest Detroit-area neighbourhood today in the latest effort to find the remains of Teamsters boss Jimmy Hoffa, who disappeared in 1975.

There was no immediate sign of human remains, but test results could be ready by Monday, Roseville police Chief James Berlin said.

"We're not sure if anything is down there. That's what this is all about," Berlin said.

They drilled the concrete floor of a shed attached to a driveway where a recent radar test revealed a shift in the soil. The latest investigation was launched after a man told police that he saw a body being buried under the driveway 35 years ago and "thinks it may have been Jimmy."

'Part of me wishes it was Mr. Hoffa, just to bring closure to his family.'—James Berlin, Roseville, Mich., police chief

Could this search be the one that solves the mystery? Don't get excited: Authorities have already said they don't think the timeline adds up and that it's unlikely Hoffa's body is there. He was last seen July 30, 1975, outside a restaurant in Oakland County, more than 50 kilometres to the west.

The homeowner, Patricia Szpunar, 72, has lived there since 1988. She said her son uses the 12-by-12 shed to store two work benches and his motorcycle.

Police detectives appeared two weeks ago and said they may need to search her yard for a dead body.

"I laughed at them," Szpunar said Friday as the work began. "I looked at them and said, `What? Do you think Jimmy Hoffa is buried in my backyard?' ... They just looked at me, and asked why I said Jimmy Hoffa."

Recently retired Detroit FBI chief Andrew Arena is among the doubters that the latest report will check out.

"You've got to check it out, but this doesn't sound right," he told The Associated Press. "The working theories that have developed over the years, this really doesn't fit any of those. If this was the mob and they killed somebody, I just don't see them burying the body basically at the intersection of a residential neighbourhood with this guy standing there."

Berlin said he's not claiming it's Hoffa under the slab, but they are "investigating a body that may be at the location."

He told CBC News at the scene that police had "credible information, and we had to follow through with that."

"Part of me wishes it was Mr. Hoffa, just to bring closure to his family," Berlin said. "I don’t believe it is Mr. Hoffa. But I don’t know what it is."

Neighbours express doubt

CBC also spoke to neighbours of the home where the digging took place, and said they were skeptical that Hoffa's remains were there.

"It’s not going to be Hoffa. Hoffa’s not in Roseville. He’s not buried under a sidewalk," Steve Kowalik said. "This is going to be one of those wild goose chases like the past.

"I just feel sorry for the neighbours that live on the street. They didn’t ask for all this."

Veronica Markstron came to see what she called a media circus.

"It’s far-fetched to think that he’s here. But they have to investigate everything," she said of police.

Feisty and iron-willed in contract talks, Hoffa was an acquaintance of mobsters and adversary to federal officials. He spent time in prison for jury tampering.

The day he disappeared, Hoffa was supposed to meet with a New Jersey Teamsters boss and a Detroit mafia captain. He was declared legally dead in 1982.

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Jimmy Hoffa was last seen July 30, 1975, outside a restaurant in Michigan's Oakland County, more than 50 kilometres to the west of a Roseville home where investigators dug underneath a shed to determine if the Teamsters Union boss was buried there. (Associated Press)

Previous tips led police to excavate soil in 2006 at a horse farm more than 160 km north of Detroit, rip up floorboards at a Detroit home in 2004 and search beneath a backyard pool north of the city in 2003.

There were even rumours that Hoffa's remains were ground up and tossed into a Florida swamp, entombed beneath Giants Stadium in New Jersey or obliterated in a mob-owned fat-rendering plant.

Roseville is one of several inner-ring communities that grew quickly as unionized auto factory workers left the city in search of nicer homes and bigger yards.

News of the latest search has brought attention to the mostly working- and middle-class suburb from the curious and naysayers. Slowly moving vehicles have clogged the residential street as camera-wielding neighbors snapped photos for keepsakes.

"I believe it's him. My sister said it is, and she's a psychic," said Mike Smith after ambling up to the home Thursday and shying a bit from the yellow police tape stretched across the driveway.

Theories about Hoffa's whereabouts abound

One local theory that has endured was that the body was beneath the foundation of a downtown Detroit hockey stadium, said 57-year-old Cindi Frank, who snapped photos Thursday of the driveway.

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The soil samples from underneath the shed of this Detroit-area home will be analysed to determine if former Teamsters head Jimmy Hoffa was buried underneath the concrete. (Associated Press)

The daughter of a unionized driver and salesman for a Detroit bakery, Frank remembers conversations about Hoffa while he was alive and rumors about his fate.

"It was a family thing. Every time we'd go somewhere we'd say, `Hey, I wonder if Jimmy Hoffa is buried there?"' Frank said. "It's just been one of those unsolved mysteries that's gone on for 30-something years. If he show up in Roseville ...."

Some think the least likely spot for him to turn up might just be the place he does.

"Maybe the most inconspicuous spot might be the place to stash a body or something," said 52-year-old Andrew Kacir, who lives across from the taped off driveway.

With files from CBC News