This 12 April, 1971 file photo shows James 'Jimmy' Hoffa (L) former president of the Teamsters union, and his son James P. Hoffa (C) as they wait at the Greater Pittsburgh Airport where they were changing planes enroute to the federal prison in Lewisburg, Pennsylvania after visiting 'Jimmy' Hoffa's wife at a hospital in San Francisco.(JERRY SISKIND/AFP/Getty Images)
ROSEVILLE, Mich. (CNN) -- Things heated up in one of the nation's most famous cold cases Friday. Police in Roseville, Michigan followed up on a tip that could lead them to the remains of Jimmy Hoffa.
What unfolded outside a suburban Detroit home Friday was either a bad tip, or a real tipping point in the search for Jimmy Hoffa.
The teamsters leader hasn't been seen since July 30, 1975. He's presumed dead, but his body has never been found.
Then, last month a tipster who says he was afraid to speak out before, told police he saw someone buried here long ago. Roseville Police Chief James Berlin says, "He believes it's Mr. Hoffa because he saw when the body was allegedly interred, it was the day of, or a day after, Mr. Hoffa disappeared."
Police say the tipster seemed credible because he didn't try to embellish the story. An initial scan showed something under the concrete, but it's not clear just what. Dan Moldea says, "It could be a dead body--if not Hoffa, then somebody else---or it could be the root of a tree, who knows?"
Police drilled for two soil samples, which will be analyzed by Michigan State University to see if they show human remains. It would take further DNA testing to determine if they're Hoffa's remains.
Police doubt the mystery is solved. Berlin says, "I don't think it's Mr. Hoffa--it'd be great if it was because I'd love to bring closure to his family and the hundreds of thousands of teamsters that idolize this man, and just to Southeastern Michigan."
A former FBI special agent says the mob would never have taken Hoffa's body to this residential neighborhood, too many people could have noticed.
But if indeed there was a burial here that escaped attention hen, this discovery most certainly would not.
Police say the soil samples results should be available by late Monday but add the digging didn't turn up any bones or body parts.
The people who own the property where the digging took place today moved in after the alleged burial.
There have been other potential leads and searches for Hoffa in the past, investigators have removed floor boards from a home, and torn down a horse barn, with no success.