MILFORD TOWNSHIP, Michigan – The FBI said it was searching property northwest of Detroit for clues to the disappearance of Jimmy Hoffa, a powerful union leader who was last seen more than 30 years ago. TV newscasts showed people with shovels and freshly turned dirt at the site.

Agent Dawn Clenney, an FBI spokeswoman, said the bureau executed a search warrant Wednesday in Milford Township, about 35 miles from Detroit.

Investigators are looking for “evidence of criminal activity that may have occurred under previous ownership” on the property, Clenney said.

Asked if they were looking for Hoffa’s remains, she said, “Could be,” but declined to comment further.

A law enforcement source in Washington, D.C., said Wednesday’s search was based on information developed several years ago and verified more recently.

There was suspicious activity on the farm the day Hoffa vanished, with a backhoe appearing near a barn, the source said, speaking on condition of anonymity because the investigation is continuing.

Organized crime figures had used the area for meetings, but the location was never used again after Hoffa disappeared, the source said.

The Teamsters leader was last seen in July 1975 at a Michigan restaurant.

Reporters were not allowed on the property, described by local media as a horse farm. Images shot from news helicopters showed about a dozen people, some with shovels, standing by an area of newly turned dirt.

Deb Koskovich, 52, said one of her neighbors told her after she moved next door to the farm in 1985 that Hoffa was buried there.

“He laughed and we laughed and that was the end of that,” said Koskovich, adding that she would be surprised if Hoffa’s remains were found. “I never thought about it again until today.”

Clenney said the bureau receives numerous leads about Hoffa and “this was one we felt we needed to follow up on.”

In May 2004, authorities ripped up the floorboards of a Detroit home where Frank Sheeran, a one-time Hoffa ally, had claimed he shot Hoffa to death. But no evidence related to the infamous, unsolved killing was found.