FBI investigators searched for the remains of missing labor leader Jimmy Hoffa in a rural area about 35 miles northwest of Detroit on Wednesday.
The FBI issued a statement that said it was acting on new information.
Officials cordoned off an 85-acre area in Milford Township and could be seen digging on the property, according to ABC News affiliate WXYZ.
Hoffa, who was credited with making the Teamsters one of the most powerful labor unions in the country, was convicted along with six others of fraud and conspiracy in 1964 for diverting more than $1 million in union funds for personal use. He was sentenced to 13 years in prison, but was released when President Nixon commuted his sentence to time served in 1971. His release was dependent on the condition that he be barred from union activities for 10 years.
Hoffa planned to fight that order and rejoin the Teamsters when he disappeared from the parking lot of the Machus Red Fox restaurant in the Detroit suburb of Bloomfield Hills, Mich., on July 30, 1975.
In the 30 years since his disappearance there have been numerous rumors about Hoffa's ultimate whereabouts. Most recently, noted mob hitman Richard "the Iceman" Kuklinski, who died in prison earlier this year, claimed that Hoffa's body was compacted in a car that later became scrap metal in New Jersey.
In 2004, investigators searched a Detroit home where another mobster claimed Hoffa was killed. Investigators ruled that blood found in the house was not Hoffa's.
ABC News affiliate WXYZ contributed to this report.