(CNN) -- A man convicted of crimes in connection with Detroit's organized-crime family claims to know where Teamsters boss Jimmy Hoffa's body was buried in 1975.
Anthony Zerilli, 85, told New York's NBC 4 that Hoffa was buried in a Michigan field about 20 miles north of where he was last seen on July 30, 1975.
"I'm as certain as I could possibly be," Zerilli told the station. "If I had money, I'd like to bet a big sum of money that he's buried (there)."
Zerilli said the plan was to bury Hoffa in a shallow grave, then move his body to a different location. The latter part of the plan fell through, and his body was left in Oakland County, Michigan.
In an interview with CNN on Monday, former U.S. attorney and chief of the Eastern District of Michigan's Organized Crime Strike Force Keith Corbett said there are very few people, if any, who would be more likely to know about Hoffa's disappearance than Zerilli.
"Tony Zerilli was in a very high position within the Detroit organized crime family for decades," Corbett said. "This is a man who would have been in the know about all matters, especially what happened to Jimmy Hoffa."
Corbett, who prosecuted Zerilli in several cases in the 1980s and '90s, says Zerilli was the head of the Detroit organized crime family from 1970-1975, but was in prison himself when Hoffa disappeared.
In 2005, Zerilli was sentenced to 71 months in prison for racketeering and extortion. He was released in 2008.
In his interview with NBC 4, Zerilli denied playing any part in Hoffa's disappearance, and said Hoffa did not deserve what happened to him.
"If I wasn't away (in prison) I don't think it would have ever happened," Zerilli told the station. "That's the only thing I can tell you."
The FBI declined to comment on Zerilli's claims.
Corbett, however, told CNN he thinks the FBI will be taking Zerilli's words seriously, and will likely see if they can acquire a search warrant for the property in Michigan.
Hoffa's disappearance and presumed death has vexed investigators for almost four decades. As recently as October, soil samples were taken from a home in the suburban Detroit community after a tipster claimed he saw a body buried in the yard a day after Hoffa disappeared in 1975.
The soil samples were tested, and showed no evidence of human remains or decomposition.
One of the most powerful union leaders at a time when unions wielded a great deal of sway in many elections -- and when some unions were notoriously tied to organized crime -- Hoffa was forced out of the organized-labor movement when he went to federal prison in 1967 for jury tampering and fraud.
Then-President Richard Nixon pardoned him in 1971 on the condition that he not try to get back into the union movement before 1980.
Hoffa, then 62, was last seen on July 30, 1975, outside a Detroit-area restaurant.
He was there ostensibly to meet with reputed Detroit mob enforcer Anthony Giacalone and Genovese crime family figure Anthony Provenzano, who was also a chief of a Teamsters local in New Jersey. Giacalone died in 1982; Provenzano died in 1988 in prison.
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.
"I'd like to just prove to everybody that I'm not crazy," Zerilli told NBC 4.
"What happened, happened while I was in jail, and I feel very, very bad about it ... (it) should have never happened to Jim Hoffa."