A Missouri man said he was shocked to discover the dead body of an infant stashed in his mother’s freezer for decades.

Adam Smith said he was cleaning out the south St. Louis apartment where his mother lived for 20 years last week, following her death from lung cancer. He said he came across a mysterious box she had kept in the freezers of her various apartments since he was a child.

When he asked her about the box in the past, he was told it was none of his business.

Smith said he never looked inside of the box because he assumed it was piece of his mother’s wedding cake.

What he found was something much different, however.

“There was a pink blanket, baby blanket, and when I reached down and touched it and I could feel a foot,” he told local television station KTVI. “And I could see the baby's head with hair, hair was still attached to it, smooth.”

Police responded to the apartment on early Sunday morning. They said they’re investigating the death as “suspicious.”

Smith said he’s distraught thinking about the possibility the infant may have been his sister.

“Who absolutely keeps their own child in a box for this long and never talks about it,” he said. “I just have so many thoughts. It’s just insane.”

The St. Louis man said he’s also concerned about what may have happened to the infant.

“I have to wait for the autopsy to see if that baby ever took a breath and I cannot help it to think she might have done something to it. I just can’t help it,” he said.

Smith said his mother once told him she lost a child at birth. He said he’s also heard from one of his relatives that his mother had twins at some point, but lost one of them at birth and put the other one up for adoption.

“I wanted some kind of closure and I feel like I may never get any closure because my mom’s gone,” he said.