St. Louis, July 31 -- A St. Louis man says a box that had been in his mother's freezer for decades contained the mummified remains of a newborn baby, which he discovered while cleaning out her home after she died.

Adam Smith told St. Louis media outlets that he opened the cardboard box Sunday expecting to find something like the top of his mother's first wedding cake or money because she never had a bank account. Instead, he says he found an infant's body and a pink blanket.

St. Louis police confirmed that they are investigating a "suspicious death" involving an "unknown infant" found inside the home and that autopsy results were pending. However, police would not answer questions Tuesday beyond an incident summary released Monday. That...