Detroit police confirm another suspected human organ has been discovered at a wastewater treatment plant in southwest Detroit.

This is the third suspected organ to be found in a week. Others were discovered Saturday, Dec. 16; and Friday, Dec. 15.

They suspected organs were found at the Great Lakes Water Authority Water Recovery Facility, 9300 W. Jefferson in Detroit, which opened in 1940 and is the largest wastewater treatment facility in the U.S.

The plan treats sewage and runoff water before returning it to the Detroit River.

Part of the process includes filtering out debris.

"On Friday, staff members noticed an object in the Water Resource Recovery Facility's (formerly known as Wastewater Treatment Plant) wastewater screening area -- the area that filters out debris from the wastewater before it goes into the treatment process," said Water Authority spokeswoman Amanda Abukhader. "Staff members immediately notified the Detroit Police Department, who responded to the scene and took custody of the object.

"On Saturday, a second object was observed in the same area, and staff followed the same protocol, notifying DPD. We have no further information on what DPD has identified the object to be, or where it entered the wastewater system."

Abukhader said the objects present no public heath threat.

The Wayne County Medical Examiner's Office has received the suspected organs from the Detroit plant and is investigating further to determine if they are human.

"The (medical examiner's office) did receive tissue," spokeswoman Lisa Croff said. "They have not confirmed whether or not it is human. It's been sent out for testing."

During the 13 months preceding October 2013, there were several discoveries of body parts, including hunks of human flesh, in the Macomb County sewer system.

The source was never determined, but some officials suggested the body parts could have illegally entered the sewage system from medical waste facilities.