"I'm finding out my mom wasn't who I thought she was," Adam Smith said

Man Finds 'Mummified' Baby's Corpse in His Mom's Freezer After Her Death

A Missouri man has been left reeling after learning his late mother left behind a horrifying secret: she’d seemingly been storing a dead baby in the family’s freezer for nearly 40 years.

Adam Smith had noticed a mysterious cardboard box in his mother Barbara’s freezer for his entire life, but thought it was a wedding cake top, he told NBC affiliate KSDK.

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“I’ve asked her several times. It was either a no-no conversation, [or] she blew me off,” he recalled.

But after Barbara died of lung cancer on July 21, Smith made a shocking discovery as he went through her things in the St. Louis apartment she’d lived in for 20 years.

“I pulled [the box] out and … I grabbed this knife and I just cut through the plastic and opened it up,” he told KSDK. “And that’s when I found a frozen baby in there.”

Smith, 37, claimed that the “mummified” infant was wrapped in a pink fleece blanket, with its skin and hair still intact.

“I just freaked out. I put it back into the box and I called police right away,” he said.

A spokesperson for the St. Louis Police Department confirmed to PEOPLE that an investigation is ongoing, and is being treated as a “suspicious death” pending an autopsy.

The alarming find has shaken Smith, who told the St. Louis Post-Dispatch that he’s since learned more about his mother than he’d never known, including the fact that she once gave birth to a set of twins, one of whom was stillborn.

“I’m finding out my mom wasn’t who I thought she was,” he said.

Smith, who has a 45-year-old sister, has also speculated that his mother’s intense secrecy over the box’s contents could suggest she was allegedly responsible for the baby’s death.

“Even as she was on her deathbed, she never told me what was in that box,” he said. “That’s what makes me think maybe she did something to this baby and didn’t want to tell anyone because she was afraid she would get in trouble.”

Though he’s estranged from his father, Smith told the Post-Dispatch he reached out to him on social media to inform him of the discovery, only to be told that his father recalled Barbara being pregnant on their first date, and not pregnant the next time he saw her.

Smith also remembered a moment from his childhood in which Barbara lamented the death of her oldest child, a girl named Jennifer, on what would have been her 21st birthday.

“Finding this, I’m more confused, angry, and I just want to find closure,” he told KSDK. “I want to know more answers.”

The Post-Dispatch reports that Smith was questioned by police for two hours, and gave a DNA sample.