Just conceivably, beneath the drive of a modest house in the suburbs of Detroit, there lies the answer to one of America's most enduring mysteries: what happened to Jimmy Hoffa?
Hoffa, one of America's most powerful post-war union leaders, disappeared without trace on a summer afternoon 37 years ago at a restaurant some 22 miles east of where his remains may now lie.
The general assumption is that he was victim of a mafia killing. For decades the International Brotherhood of Teamsters, the coalition of freight, shipping and transport workers who he served as president for 13 years, were riddled with corruption and links to organised crime. Hoffa himself spent four years in prison after being convicted of bribery and fraud, before being pardoned in 1971 by President Richard Nixon, on the condition that he stay out of union activities until 1980.
No-one has ever been charged in connection with his disappearance, but in a detailed 1976 report on the case, the FBI concluded he was killed on the orders of mob bosses who feared his return to power would threaten their control of the union's lucrative pension fund.
Over the years countless theories have been advanced about Hoffa's fate. Several burial sites have been reported – the most recent of them in 2006, when the FBI spent $250,000 on a convict's tip that his remains were to be found at a horse farm once owned by a corrupt Detroit Teamsters official. Other tales have Hoffa's final resting place as the concrete foundations of the old Giants football stadium a few miles west of Manhattan, or a support pillar of a New Jersey freeway. Others have claimed his body was rendered for fat in a mob-controlled food processing plant, even that he was fed to alligators in Florida.
The odds are this latest lead will prove to be a wild goose chase too. It began with a tip to Dan Moldea, an investigative journalist, from a man who claims to have seen someone being buried at the house in Roseville around the time that Hoffa disappeared, on 30 July, 1975.
"This is not a mob guy," Mr Moldea told The Detroit News about the tipster, who has terminal cancer. "He's not connected. He's just a guy in the right place at the right time, or the wrong place at the wrong time. He's scared to death right now."
The house is about a half-hour's drive from where Hoffa was last seen, at what was then the Machus Red Fox restaurant. Hoffa went there for a meeting with Anthony Giacalone, a member of the Detroit mafia, and Anthony Provenzano, a New Jersey Teamsters official with strong mob connections.
But neither showed up, and around 20 minutes later he went outside to the car park and was never seen again.
Initial tests at the site have indicated an "anomaly" and further soil tests are being carried out today.
"If they are positive, we will then start excavating," Roseville police chief James Berlin said.
"It could be anybody down there; could be nobody. It could be a dog. We are not making the assumption it is Jimmy Hoffa."