Updated

The FBI is looking into whether the death of a U.S. Census worker found hanged from a tree with the word "fed" scrawled on his chest in Kentucky is linked to anti-government sentiment.

A law enforcement official, who was not authorized to discuss the case and requested anonymity, did not disclose what type of instrument was used to write the word on the chest of Bill Sparkman, who was supplementing his income by doing Census field work.

Sparkman was found Sept. 12 near a Kentucky cemetery in a remote patch of Daniel Boone National Forest. An autopsy report is pending.

Police said Sparkman died of asphyxiation and are trying to determine if he was murdered, committed suicide or died accidentally — but they have not yet ruled the death a homicide, FOX41.com reported.

When Sparkman, 51, told retired trooper Gilbert Acciardo that he would be going door-to-door to collect census data in rural Kentucky, the former cop had a stern warning for his friend: "Be careful."

"Even though he was with the Census Bureau, sometimes people can view someone with any government agency as 'the government.' I just was afraid that he might meet the wrong character along the way up there," said Acciardo, who directs an after-school program at an elementary school where Sparkman was a frequent substitute teacher.

The Census Bureau has suspended door-to-door interviews in rural Clay County, where the body was found, until the investigation is complete, an official said.

Manchester, the main hub of the southeastern Kentucky county, is an exit off the highway, with a Walmart discount store, a few hotels, chain restaurants and a couple of gas stations. The drive away from town and toward the area where Sparkman's body was found goes through sparsely populated forest with no streetlights, on winding roads that run up and down steep hills.

Manchester Police Chief Jeff Culver, whose agency is not part of the investigation because the death was outside city limits, said the area where Sparkman was found has a history of problems with prescription drug and methamphetamine trading.

"That part of the county, it has its ups and downs. We'll get a lot of complaints of drug activity. They'll whittle away, then flourish back up," Culver said. He said officers last month rounded up 40 drug suspects, mostly dealers, and made several more arrests in subsequent days.

FBI spokesman David Beyer said the bureau is assisting state police and declined to discuss any details of the crime scene. Agents are trying to determine if foul play was involved and whether it had anything to do with Sparkman's job as Census worker, Beyer said. Attacking a federal worker during or because of his federal job is a federal crime.

Lucindia Scurry-Johnson, assistant director of the Census Bureau's southern office in Charlotte, North Carolina, said law enforcement officers have told the agency the matter is "an apparent homicide" but nothing else.

Census employees were told Sparkman's truck was found nearby, and a computer he was using for work was inside, she said.

Sparkman's mother, Henrie Sparkman of Inverness, Florida, told The Associated Press her son moved to Kentucky to direct the local Boy Scouts of America. He later became a substitute teacher in Laurel County, adjacent to the county where his body was found.

She said investigators have given her few details about her son's death. They did tell her his body was decomposed and haven't yet released it for burial.

"I was told it would be better for him to be cremated," she said.

Acciardo said he became suspicious and went to police when Sparkman didn't show up for work at the after-school program in Laurel County for two days. Authorities immediately investigated, he said.

"He was such an innocent person," Acciardo said. "I hate to say that he was naive, but he saw the world as all good, and there's a lot of bad in the world."

Sparkman had worked for the Census since 2003 in five counties in the surrounding area, conducting interviews once or twice a month. Much of his recent work had been in Clay County, officials said.

The Census Bureau has yet to begin door-to-door canvassing for the 2010 head count, but thousands of field workers are doing smaller surveys on various demographic topics on behalf of federal agencies. Next year, the Census Bureau will dispatch up to 1.2 million temporary employees to locate hard-to-find residents.

Mary Hibbard, a teacher in Manchester, said she recognized Sparkman on the news as the census worker who visited her house this summer for about 10 minutes. Hibbard said he asked some basic questions including the size of her house, how many rooms it had and how much she paid monthly for electricity.

"I know he has a Christian background," she said. "You come to my house, we're going to talk religion."

Hibbard said she thinks most people in the area were shocked by the death.

"I think the negative publicity of it is a stigma on our county. It makes people think less of us even though this is an isolated incident."

The Census Bureau is overseen by the Commerce Department.

"We are deeply saddened by the loss of our co-worker," Commerce Secretary Gary Locke said in a statement.

Kelsee Brown, a waitress at Huddle House, a 24-hour chain restaurant in Manchester, when asked about the death, said she thinks the government sometimes has the wrong priorities.

"Sometimes I think the government should stick their nose out of people's business and stick their nose in their business at the same time. They care too much about the wrong things," she said.

Appalachia scholar Roy Silver, a New York City native now living in Harlan County, Kentucky, said he doesn't sense an outpouring of anti-government sentiment in the region as has been exhibited in town hall meetings in other parts of the country.

"I don't think distrust of government is any more or less here than anywhere else in the country," said Silver, a sociology professor at Southeast Community College.

The most deadly attack on federal workers came in 1995 when the federal building in Oklahoma City was devastated by a truck bomb, killing 168 and injuring more than 680. Timothy McVeigh, who was executed for the bombing, carried literature by ultra-right-wing, anti-government authors.

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The Associated Press contributed to this report.