Police in South Florida have launched a death investigation after a beachgoer discovered what appeared to be a fetus that had washed up on the shore.

The Miami Beach Police Department said it was called to the beachside scene on Tuesday afternoon after someone spotted the human remains and alerted Ocean Rescue, which then called the police.

Police believe the remains belong to an unborn infant, but there are many unknowns about it how it ended up there, whether from a miscarriage or the mother's doing, police spokesperson Christopher Bess told USA TODAY Wednesday.

"Honestly, due to the elements, it's a beach with saltwater, sand... the medical examiners office will have to help us with this," Bess said, adding that it appeared to have washed up on shore rather than having been placed there.

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Police investigating 'unique' call about washed up fetus

Bess called the incident "unique," and said the department is thoroughly investigating the matter. He said he had not heard any updates from the medical examiner as of Wednesday morning.

A 7 News camera showed a cardboard box covering the remains at the scene on the beach. Aerial footage captured by NBC 6 showed the remains being moved with a shovel in a taped off section of the sand.

The medical examiner's office took the remains away hours after the body was found, NBC 6 reported. The Miami-Dade County medical examiner's office did not immediately respond to USA TODAY's request for comment.