A gruesome discovery at an Aiea Heights park early Thursday morning has sparked a police investigation.

The mystery surrounds who left a fetus in a park trash can and why.

Honolulu police spent several hours Thursday morning scouring Napuanani Park.

It's where Rick Sanford said he found the box while collecting bottles and cans around 7:30 a.m.

He brought it home and couldn't believe what he found inside.  Rolled up in paper towels was a human fetus.

“It was rolled up in 3 or 4 paper rolls,” said Sanford.  “It was a little boy.  I could tell it was a little boy.  It had all the parts.”

Sanford said the fetus looked a day or two old.   Sanford said as a former Army medic, he had seen his share of dead bodies.  But the sight of a dead child was very upsetting.  Plus, he had to fend off his curious dog.

“He’s jumping on me trying to get to the box.  I remember telling him, you can’t eat a human,” said Sanford.

He called the police who uncovered another strange find in a nearby garage  -- a garbage bag full of medical supplies.

Sanford said the main house on the property is rented to four Navy sailors who are on deployment.  But two women, who Sanford said was the sister of one of the men and another he didn't know, stopped by the house earlier this week.  Police are hoping to find the women to ask them a few questions.