The body of an 81-year-old woman found Sunday in a Far South Side home had been dismembered and placed in storage bins, Chicago police said Monday.

“Whoever did this put a lot of effort and time into doing this horrific act,” Chicago Police spokesman Anthony Guglielmi said.

The woman’s real estate agent had been trying to reach her for several days when he went to her home in the 1000 block of South Forest Sunday morning, Guglielmi said. When the real estate agent noticed a “foul odor” coming from the home, he called police, Guglielmi said.

Chicago firefighters then forced their way into the home, allowing police to search the property.

As police entered, they too noticed a bad smell. They then opened one of the bins and discovered what appeared to be human remains, Guglielmi said.

The Cook County Medical Examiner’s Office identified the woman as Thana Muhammad.

Chicago Police Supt. Eddie Johnson, speaking to reporters at police headquarters, described the crime scene as “very clean.”

“Right now we are relying very heavily on physical evidence from the crime scene, assuming she was murdered in this home; we don’t know for sure,” Guglielmi said.

Police had no one in custody Monday and a weapon had not been recovered, Guglielmi said, it was unclear whether the woman lived in the home alone. Authorities have not released her identity.

The medical examiner’s office conducted an autopsy on Muhammad Monday, but did not immediately rule on the cause and manner of her death pending further investigation.