The FBI says it has found no sign of the remains of former Teamsters union leader Jimmy Hoffa and is ending a dig in suburban Detroit.
The announcement was made Wednesday by Robert Foley, head of the FBI in Detroit, just a few hours after digging resumed. The dig began Monday.
Authorities have pursued multiple leads on Hoffa's whereabouts since his disappearance in 1975. He was last seen outside an Oakland County restaurant where he was to meet with a New Jersey Teamsters boss and a Detroit Mafia captain.
Investigators widened the search area and brought in a cadaver-sniffing dog on Tuesday, but apparently did not find the remains of Hoffa, who is thought to have been murdered by mobsters.
The site where FBI agents have been digging for Hoffa's remains in Oakland County is about 20 miles (32 km) north of the Machus Red Fox restaurant where Hoffa was last seen alive. The FBI opened the search after a tip from reputed mobster Anthony Zerilli.
FBI officials said the search had been widened but gave no details.
The search of the 40- to 50-square-yard area would continue at least another 48 hours, said Oakland County Sheriff Michael Bouchard. He said police and FBI officials remain optimistic but that nothing had been sent for lab analysis so far.
Bouchard said investigators had discovered concrete on the site, which could corroborate Zerilli's claim that Hoffa was buried on the site under a concrete slab.
"Obviously that was part of the original information," he said. "And it's consistent with that" information.
The FBI brought in forensic anthropologists from Michigan State University and a cadaver-sniffing dog to help search a half-acre of the site, according to a person close to the investigation who asked not to be identified.
Curious bystanders gathered on Tuesday near the field, which was blocked off by Oakland County sheriff deputies, and peered through wavy grass and trees to see agents digging and a backhoe at work.
The search for Hoffa, who was 62 when he disappeared in 1975, has spawned many theories about his final resting place, ranging from under an end zone in Giants Stadium in East Rutherford, New Jersey, to the General Motors Co headquarters in downtown Detroit and the Florida Everglades.
TIP PROMPTED SEARCH
Law enforcement officials decided to search the Michigan lot after Zerilli, 85, told the FBI that Hoffa was buried there. Zerilli's attorney, David Chasnick, told reporters the FBI spoke to his client over the past seven or eight months and that the agency believes "100 percent" that Hoffa is buried there.
"This was a guy who was intimately involved with some of the players who would be well informed as to where the body would be placed," Chasnick said.
According to a 21-page manuscript that Zerilli wrote and is selling online, Hoffa was dragged out of a car, bound and gagged, hit with a shovel and then being buried alive under a cement slab in a barn on the property.
FBI officials had no comment on Zerilli's assertions.
Hoffa, the father of current Teamsters President James Hoffa, led the union from 1957 to 1971 and went to prison for fraud and jury tampering. He was released in late 1971, when President Richard Nixon commuted his sentence.
Authorities have long thought Hoffa was ordered killed by organized crime figures to prevent him from regaining control of the Teamsters.
Investigators have checked thousands of leads over the years. In September 2012, police took a soil sample from behind a private home in Roseville, Michigan, after receiving a tip that Hoffa might be buried there.
© 2013 Thomson/Reuters. All rights reserved.