"We received information from an individual who saw something," Roseville Police Chief James Berlin told the Detroit Free Press Wednesday. "The information seemed credible, so we decided to follow up on it."
A radar scan of the driveway by the Department of Environmental Quality determined there was an anomaly two feet under the surface of the driveway.
"We do not know if this is Jimmy," Berlin warned, adding it could be a dead dog or a tree root.
Berlin said authorities plan to take a core sample of the ground and test it for human DNA. If the sample comes back positive for human remains, the driveway will be excavated.
Hoffa was last seen in 1975 in a restaurant parking lot after an alleged meeting with two men who had connections to the mob. The FBI theorized the men killed Hoffa to prevent him from regaining the Teamsters presidency, possibly threatening the mob's influence over the union and access to pension funds.