Human remains found in a Phoenix wastewater sewer line included bones and likely were too large to have been flushed down a toilet, police said Friday.
Other entry points to the sewer system include manholes and homes' cleanout caps.
However, Officer James Holmes said it's not known how the remains got into the sewer line before they were found Wednesday night by workers investigating a complaint about sewer water backing up.
Police on Thursday completed a search of the sewer line, and the remains have been turned over to medical examiners, Holmes said.
Police have said the remains appear to be from an adult, but Holmes said it could be a week or longer before investigators receive any additional information from medical examiners.
Unanswered questions include the person's gender and ethnicity as well as when the remains were placed in the sewer system and how the person died.
"That's going to have to come from the medical examiner," Holmes said.
The case is being treated as a homicide.
Nobody in the neighborhood or elsewhere has come forward to suggest who the person was, and more information about the remains is needed from medical examiners to help identify the person by checking missing-person reports, he said.
"We're all waiting right now," Holmes said.
Meanwhile, the Water Services Department said two employees who found the remains are receiving counseling services under the city's employee assistance program.
Department spokeswoman Yvette Roeder said city officials wanted to assure residents that the sewer line was separate from and not connected to the pipe system that provides drinking water.
