ROSEVILLE, Mich. -

Police have wrapped up their search for Jimmy Hoffa's remains at a home in Roseville, Michigan, reports WDIV-TV in Detroit.

They began drilling outside the home Friday morning just before 10 a.m. and completed their search shortly after 11 a.m. Jimmy Hoffa was a labor strongman whose disappearance is one of the most notorious and mysterious in U.S. history.

A tipster told police that a body was buried at the spot in Roseville, Michigan, at around the same time the Teamsters boss disappeared in 1975.The tipster did not claim it was Hoffa's body, authorities said.

Machus Red Fox Map

Roseville police chief James Berlin said Friday there were no visible signs of human remains in the area that was searched, but soil samples will be sent to Michigan State University for testing.

However, a source said that the scene will be held as a crime scene. There is no word on what was found that leads them to classify the area that way.

About Jimmy Hoffa

Hoffa remains among America's most famous, and in many ways infamous, missing people. His presumed death has vexed investigators for four decades.

One of the most powerful union leaders at a time that unions wielded a great deal of sway over elections -- and were notoriously tied to organized crime -- Hoffa was forced out of the organized labor movement when he was sent to prison in 1967.

He served time for jury tampering and fraud at a federal penitentiary in Lewisburg, Pennsylvania, until being pardoned by President Richard Nixon on December 23, 1971 -- on the condition that he not try to get back into the union movement before 1980.

Two weeks before Hoffa's disappearance in 1975, federal investigators discovered that hundreds of millions of dollars had been stolen from the Teamsters' largest pension fund, Time magazine points out in its list of the top 10 most famous disappearances.

Hoffa, then 62, was last seen July 30, 1975, at Machus Red Fox restaurant in suburban Detroit. He was there ostensibly to meet with reputed Detroit Mafia street enforcer Giacalone and Anthony Provenzano, chief of a Teamsters local in New Jersey, who was later convicted in a murder case. Both men have since died.

Hoffa believed Giacalone had set up the meeting to help settle a feud between Hoffa and Provenzano, but Hoffa was the only one who showed up for the meeting, according to the FBI.

Giacalone and Provenzano later told the FBI that no meeting had been scheduled.

The FBI said at the time that the disappearance could have been linked to Hoffa's efforts to regain power in the Teamsters and to the mob's influence over the union's pension funds.

Jimmy Hoffa 2 Police and the FBI have searched for Hoffa intermittently ever since.

In September 2001, the FBI found DNA that linked Hoffa to a car that agents suspected was used in his disappearance.

In 2004, authorities removed floorboards from a Detroit home to look for traces of blood, as former Teamsters official Frank Sheeran claimed in a biography that he had shot Hoffa. Sheeran died in 2003.

Investigators ruled blood found in the house was not Hoffa's. The FBI has a sample of his DNA from a hair brush.

Two years later, the FBI razed a horse barn in Michigan following what it called "a fairly credible lead."

But the disappearance remains unsolved.

But over the years, numerous theories have been floated. In 1987, Joe Franco -- a former Hoffa strong-arm -- and a New York Times reporter published "Hoffa's Man," which Fortune described as "the hair-raising inside story of Jimmy Hoffa."

"Rather than being kidnapped by rival union forces as law enforcement authorities have long speculated, Franco says Hoffa was abducted by two federal agents," Fortune reported. "He thinks they drove Hoffa to a nearby airport, took off in a small plane, and pushed him out over one of the Great Lakes. Franco says he did not tell federal investigators this bizarre, and unverifiable, story because they would not grant him immunity."

Hoffa's son, James P. Hoffa, is the current president of the Teamsters.

PHOTOS: Search begins for Jimmy Hoffa's remains in Roseville

Published On: Sep 28 2012 11:44:32 AM EDT

Michigan investigators began taking soil samples Friday from underneath a driveway in Roseville in the latest effort in a decades-long investigation to figure out where missing Teamsters boss Jimmy Hoffa may be buried.

hoffa 7
1 / 8