By Joseph Lichterman
OAKLAND TOWNSHIP, Mich., June 18 (Reuters) - FBI agents in suburban Detroit widened their search of an overgrown field Tuesday for the remains of former Teamsters union boss Jimmy Hoffa, who disappeared nearly 38 years ago and is thought to have been murdered by mobsters.
The search for Hoffa along with a dig at the former home of late New York mobster Jimmy Burke, the suspected mastermind of the 1978 Lufthansa cargo heist, and the trial of Boston gang leader James "Whitey" Bulger made Tuesday especially notable for followers of U.S. organized crime cases of the 1970s and '80s.
FBI agents have been digging for Hoffa's remains since Monday when a backhoe was driven onto a field in Oakland County, 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.
They broke for the night and resumed Tuesday morning. FBI officials said the search had been widened but gave no further details.
Oakland County Sheriff Michael Bouchard told reporters on Tuesday the search of the 40- to 50-square-yard (33- to 40-square meter) area would continue at least another 48 hours. He said police and FBI officials remain optimistic but that nothing had been sent for lab analysis so far.
The FBI brought in forensic anthropologists from Michigan State University and a cadaver-sniffing dog from Michigan state police to help search a half-acre (0.20 hectare) 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 the 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 Everglades in Florida.
In Michigan, law enforcement officials decided to comb the 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 the agency believes "100 percent" 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 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 was imprisoned for fraud and jury tampering in his final years. 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 he might be buried there.
At the Oakland field on Tuesday, Terry Moore, 60, of nearby Shelby Township came to watch the activity. While he didn't expect Hoffa's remains to be found in the latest search, he wanted to see for himself. "This is sort of history," he said.
In Boston, James 'Whitey' Bulger is standing trial on accusations he committed or ordered 19 murders while running Boston's Winter Hill Gang in the 1970s and '80s.
In New York, the FBI was digging inside Burke's former home looking for human remains, a source familiar with the search said. Burke, also known as "Jimmy the Gent," died in prison in 1996 while serving time for the murder of a drug dealer.
Actor Robert De Niro played a character inspired by Burke in Martin Scorsese's 1990 hit movie "Goodfellas," which featured the famed robbery at John F. Kennedy International Airport, which netted almost $6 million. Jack Nicholson played Hoffa in 1992's "Hoffa."