Jerry Siskind / AFP - Getty Images file
Jimmy Hoffa and his son, James P. Hoffa, who later also became president of the Teamsters, in a 1971 photo.
Updated at 3:40 p.m. ET: Soil tests indicate that no human remains are buried beneath a shed in Roseville, Mich., where authorities were investigating the possibility that the late Teamsters President Jimmy Hoffa might have been buried, officials said.
Scientists at Michigan State University tested two samples from a home in Roseville, a suburb of Detroit, after an unidentified tipster told authorities that he witnessed a body being buried there the day after Hoffa disappeared in July 1975.
Those tests came up negative for human remains, Roseville police said Tuesday.
The lead appears to be yet another dead end in the search for Hoffa, who ran the International Brotherhood of Teamsters, the country's biggest labor union, from 1957 to 1971. It joins a long line of false leads that have fueled conspiracy theories for years.
Investigators searching for the remains of notorious Teamsters boss Jimmy Hoffa have come up dry after pursuing a lead in suburban Detroit. NBC's Brian Williams reports.
Investigators and other experts had said that they doubted that Hoffa was at the site.
Andy Arena, the former FBI special agent in charge for Detroit, said that while his "gut feeling is that this person saw something," it defies common sense to believe that the Mafia would have buried the body in broad daylight in a busy suburban area.
"If this guy was standing there watching this, and it was Jimmy Hoffa, he would have been in the hole with him," Arena said.
Dan Moldea, author of "The Hoffa Wars" and numerous other books on organized crime, also said he "never thought that Hoffa was here, ever."
More content from NBCNews.com:
- A week later, search still on for 73-year-old accused of killing daughter-in-law
- Video: Like hurricanes, winter storms to get names too
- Cell phone video shows cop striking woman after Philadelphia parade
- State Dept: Missing American journalist Austin Tice believed held by Syria regime
- NYPD commissioner blames rise in crime rate on Apple thefts