Will the remains of Jimmy Hoffa actually be uncovered this week?

Investigators, a tipster and curious onlookers hoped for just that Monday in Michigan as the FBI led a new search for Hoffa's body in the field.

Their optimism was tempered, given that it is the latest in a series of digs since the Teamsters boss went missing nearly four decades ago.

Hoffa was kidnapped on July 30, 1975, in the parking lot of what was then the Machus Red Fox restaurant in Bloomfield Township, Mich.

The search resumed after Tony Zerilli, 85, the son of reputed former mob boss Joseph Zerilli, claimed to know where Jimmy Hoffa is buried.

That led officials to a field in rural Oakland Township, Mich.

Earlier this year, Zerilli claimed Hoffa was struck with a shovel and then buried alive on the property, with a slab of concrete placed over the body.

FBI Special Agent in Charge Robert Foley III of the Detroit office confirmed that the FBI was presently executing a search warrant in the grassy field.

"Because this investigation is an open investigation and the search warrant is sealed, I will not be able to provide any additional details," Foley said.

Hoffa's daughter, Barbara Crancer, a retired judge in St. Louis, said the FBI called her Sunday to alert her of the search, and she's closely following it.

She said she hadn't heard Zerilli's story until he came forward.

"We never get our hopes up," Crancer said.

"We'll let the FBI do their job, and see what happens. That's all we can do. I want everybody to know that I appreciate the FBI following up on this."

Sources at the scene said investigators were searching a concentrated area there. Tents were set up on the property, at least 500 feet off the dirt road.

The search was expected to resume Tuesday morning.

Zerilli's lawyer, David Chasnick of Novi, Mich., said Zerilli has been waiting at least eight months for the FBI to follow up on his tip, which they have.

Zerilli was in jail when Hoffa disappeared.