DETROIT (AP) - Investigators in Detroit say they have little to go on in the case of a fetus found in a municipal wastewater treatment plant.

The fetus estimated at 3 to 4 months of development was found Friday in the sewer system intake of the Detroit Water and Sewerage Department facility.

Detroit police spokesman James Tate told The Detroit News on Saturday there is no indication where the fetus came from.

The plant takes in wastewater from Detroit plus 76 other communities in the surrounding region.

Tate said investigators are not even sure if a crime occurred. He said the fetus could have come through a toilet as a result of a miscarriage.