MILFORD TOWNSHIP, Mich. -- FBI agents said nothing significant has been found following Thursday's search for the remains of Jimmy Hoffa.

Cadaver dogs were brought in to search the hole left from dirt removal at the Hoffa dig site in Oakland County, Mich.

The searchers used a backhoe to peel away the earth at the spot where they had removed concrete and asphalt that had been the barn's floor. The barn was leveled Wednesday, and pieces of the torn-down structure were hauled off to a landfill.

The digging stopped, and agents and crime scene investigators jumped in the hole to take photos and video and sift through the dirt by hand.

The Milford Township horse farm is located not far from where the former Teamsters chief vanished in 1975. No trace of him has ever been found, and no one has ever been charged in the case.

A government investigator last week said Donovan Wells gave the agency the tip that sparked the latest effort. Wells lived on the land at the time around Hoffa's disappearance.

Endless theories about what happened to Hoffa include being buried at Giants Stadium in New Jersey to being obliterated in a burned-down, mob-owned fat-rendering plant.

Last year, the FBI crime lab concluded that blood found on the floor of a Detroit home where a one-time Hoffa ally claimed to have killed him didn't belong to Hoffa.