Bill Sparkman's body was found on 12 September in a forest
US police are investigating the death of a man who was found hanged from a tree in rural Kentucky with the word "Fed" scrawled on his chest.
Bill Sparkman, 51, had been going door-to-door in Clay County collecting census data.
The FBI is investigating whether Mr Sparkman was victim of anti-government sentiment.
The Census Bureau has suspended door-to-door interviews in the area until the investigation is complete.
"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 Gilbert Acciardo, a retired policeman who knew Mr Sparkman, and had warned him to "be careful" when carrying out the census.
Mr Acciardo runs an after-school programme at a school where Mr Sparkman was a regular supply teacher.
He became suspicious and went to police when Mr Sparkman did not show up for work for two days.
Mr Sparkman's body was found on 12 September in a remote area of Daniel Boone National Forest.
The assistant director of the Census Bureau's southern office in Charlotte, North Carolina, said police had told the agency the matter was "an apparent homicide" but had given no further details.
Governor Steve Beshear gave his condolences to Mr Sparkman's family.