Police discovered a decomposed body stuffed inside a plastic bin in the home of an elderly woman that had been condemned after being overrun with more than 100 cats, authorities said.

The remains found Monday are believed to be those of 84-year-old Mary Haas. A warrant was issued for her two daughters, Pamela Haas, 48, and Candy Haas, 43, on charges of abuse of a corpse and conspiracy.

"The fact that the body was placed in a plastic container leads you to believe that it was something other than a natural death," said Dover Police Capt. Lester Boney. "But it could have been natural and this was their way of disposing of the body."

More coverage available in FOXNews.com's Crime Center.

Boney said the body was found four days after police condemned the residence, which was home to more than 100 cats and three dogs. Officers didn't find Mary Haas at that time, but Pamela Hass was there. When officers returned Monday to pick up some of the diseased cats to be euthanized, they found the human remains in a bedroom.

Neighbors said the sisters mostly kept to themselves and the mother had not been seen in about a year. The residence reeked of animal feces, they said.

"There were days when it would make you gag," said neighbor Donald Merchant.

Visit FOXNews.com's Crime Center for complete coverage.