ROSEVILLE, Michigan (Reuters) - Police doubt former Teamsters union boss Jimmy Hoffa is buried under a suburban Detroit driveway, but someone else may be, Roseville Police Chief James Berlin said Thursday.

The search for Hoffa, who disappeared in July 1975 in what authorities believe may have been an organized crime hit, has generated thousands of leads, but no remains.

"We are treating this as a John Doe," Berlin said. "We are not making any claims whatsoever that this is Jimmy Hoffa. We do not believe that it is Jimmy Hoffa."

Police will take a core sample of soil from under the driveway Friday and turn it over to a forensic scientist from Michigan State University, Berlin said. Results might be available next week, he said.

Police were skeptical of a connection to Hoffa after they received a "credible" tip that someone had been buried there, Berlin said. Authorities had wanted to keep their search as low-key as possible.

Instead, the latest twist in the search for Hoffa has brought a surge in interest into the community, which is about 20 miles east of the restaurant where Hoffa was last seen.

"We had an individual contact our department claiming he witnessed a body be interred 35-some-odd years ago," Berlin said, adding that police were treating it as an investigation into a possible cold case homicide. The tipster believed he saw the burial the day of, or the day after, Hoffa disappeared.

Berlin said there are "some inconsistencies" with the man's timeline, but "memories fade, facts blur, so who knows."

Dan Moldea, who wrote a book on Hoffa's disappearance, "The Hoffa Wars," in 1978, said a man called him with a tip in March. Moldea was skeptical, he said, but referred the man to the FBI. After the FBI rebuffed the caller, Moldea said he suggested the man contact local police.

"We interviewed this individual, we felt his story was credible, that he did, in fact, see something," Berlin said.

Police are searching a brick ranch house on a corner lot. The driveway was marked off with yellow police tape.

"They ain't going to find nothing there," said Art Prue, 84, who has lived in the neighborhood since 1952.

Other residents were surprised by the search.

"I'm stunned," said Catherine Cole, 52, who has lived across the street from the house for 25 years. "I've never seen anything like it."

Hoffa, the father of Teamsters President James Hoffa, led the union from 1957 to 1971, spending the final years of his term in prison for fraud and jury tampering. He was released in late 1971 when President Richard Nixon commuted his sentence.

Authorities have long theorized that Hoffa was ordered killed by organized crime figures to prevent him from regaining control of the Teamsters. He had agreed to be banned from the union until 1980 as part of the deal that got him out of prison.

Michigan Department of Environmental Quality officials used ground-penetrating radar on the driveway, which detected an anomaly that warranted investigation, agency spokesman Brad Wurfel said. "We have no clear indication of what that might be, only that it appears that something was buried there," Wurfel said.

Shortly after Hoffa disappeared, the FBI took over the Hoffa investigation. A spokesman for the FBI's Detroit office has declined to comment on the reports.