Charles Zigler's girlfriend kept the body in a chair under a cover at their home in Jackson, Lt. Chris Simpson said Tuesday.
No foul play is suspected in the 67-year-old man's death, but police are investigating whether his death was concealed for reasons of financial fraud, Simpson said.
The 71-year-old woman, whose name has not been released, was not arrested.
Zigler's body was discovered July 6 after a niece asked police to check on him. It's believed he died in December 2010.
Relatives "called on him several times, inquiring, 'Where is he?' They were given excuse after excuse by the girlfriend," Simpson said. "It got to the point where they wanted to get the police involved."
Despite the presence of human remains, the house was in good shape and had no foul odor, the lieutenant said.
"She let our officers in. She was a little surprised to see them," Simpson said. "They pulled the blanket back and were alarmed to find a body underneath."
Simpson said there's a "strong possibility" that Zigler died in the chair and was never moved. Simpson would not divulge what the woman told officers about why the death was not reported.