Detroit police found no "discernible remains" on Friday when they dug up under a concrete driveway in search of long-missing labor strongman Jimmy Hoffa, police Chief James Berlin told reporters.

As the investigation continues as planned, two soil samples taken from beneath a storage shed outside a suburban Detroit home have been taken to a lab at Michigan State University for testing.

According to police, officials are expected to announce by Monday night if they've found evidence that coincides with a tipster's claim that he saw what appeared to be a body being buried at the site the day after the former Teamsters chief disappeared in 1975.

But even if human remains are discovered at the Detroit home, experts say they doubt it’s going to be those of the former Teamsters president.

"It would be great if it was, because I would like to bring closure to his family and the tens of thousands of Teamsters that idolize this man, and just the southeast of Michigan," said Berlin, of the Roseville Police Department. "This is kind of like an open wound that won't go away. Every couple of years this happens, and all you guys come out here and we have to relive it."

Police at the site of the investigation broke through a concrete floor beneath a storage shed at the home and collected two soil samples from the ground as deep as 6 feet down, Berlin said.

While the results didn't turn up bones, body parts or other evidence, he described the samples as merely "murky."

As authorities handling the investigation searched the grounds, reporters and curious onlookers congregated on the street outside the home, which reportedly once housed a gambling operation tied to Detroit's notorious organized crime community.

The search began after a tipster came forward in August to say that he believed he'd witnessed a body being buried at the home. The tipster did not come forward sooner out of fear, Berlin said.

Police followed up on the tip last month by using ground-penetrating radar that showed some sort of anomaly in the ground beneath the storage shed's concrete floor, according to police.

Reports indicate that the soil samples will be able to determine if human remains were buried at the site, but will not identify them.

If human remains are discovered, investigators would have to return for a more complete excavation, Berlin said.

CNN reports that Dan Moldea, author of "The Hoffa Wars," first spoke to the tipster in March and sent him to police.

The unidentified tipster, a former gambler, once did business with a man tied to Anthony Giacalone, an organized crime figure who was supposed to meet Hoffa the day he disappeared, Moldea told the news outlet.

Despite those links, Moldea said it seems unlikely that anyone would have been buried at the site, in full view of the neighborhood. And if a body had been buried there, little would remain, he said.

"I am very skeptical," Moldea said of the search.