Michigan police have rekindled America’s enduring fascination with the whereabouts of Jimmy Hoffa with the news that it will dig beneath a home in search of a possible burial spot on Friday. Police will take soil samples from beneath the home in Roseville, Mich., near Detroit, acting on an anonymous tip, according to the Detroit Free Press.

Hoffa, the notorious Teamsters union boss, disappeared in 1975. What exactly happened to him is still unknown but the conspiracy theories that still surround the incident number only behind those around President John F. Kennedy’s assassination. Hoffa was rumored to have run afoul of former cohorts in the mob.

“We received information from an individual who saw something,” Roseville Police Chief James Berlin told the Free Press. “The information seemed credible, so we decided to follow up on it.”

Berlin also said the Michigan Department of Environmental Quality found an “anomaly” in the soil underneath the driveway. He stressed that officials are not certain it’s Hoffa, but the informant “thought it was Jimmy because the same time this happened was the same time Jimmy disappeared.”

“It took us a while to get the proper equipment to do what we’re going to do,” Berlin told CNN. “If this is a person, they’ve been down there for 35 years. What’s a few more days?”

When he vanished Hoffa had served almost five years of an eight-to-13-year sentence for fraud, conspiracy and jury tampering. He was pardoned by President Richard Nixon on the stipulation he stay out of union activities until 1980, something the ex-Teamsters boss seemed incapable of. Hoffa is thought to have been killed by the Mafia because had he taken control of the union again he was seen as a threat to the mob’s infiltration of it.

Hoffa, who was 62 at the time of his disappearance, was last seen in the parking lot of a restaurant in Michigan’s Bloomfield Township. Trying to regain control of the Teamsters union after the prison stint, Hoffa had long been rumored to be passing through the area to meet with mob enforcer Anthony Giacalone and New Jersey Teamsters official Anthony Provenzano. The two later denied any knowledge of a meeting.

In 2001 the FBI found DNA evidence in a car that was thought to have transported Hoffa away from the restaurant parking lot. The owner of the car, Chuckie O’Brien, was Hoffa’s protégé and long suspected in taking to him to the place where Hoffa was executed. Investigators theorized that Hoffa’s corpse was incinerated or cut up in some way.

Law enforcement officials tore down a barn in 2006 in a fruitless search for Hoffa’s remains and, two years earlier, looked beneath the floorboards of an old Hoffa rival’s home. The most popular rumor was Hoffa’s burial beneath Giants stadium. Jack Nicholson played Hoffa in a 1992 movie that depicted the character being killed in a Mafia-sponsored hit.

Hoffa’s son James is the current labor leader for the Teamsters union.