Police in South Florida are working to determine the identity of a head that washed ashore near Key Biscayne on Tuesday morning.

A beach worker spotted the head, which appeared to that of a man, about 8:30 a.m. floating on the shoreline near a small island near Key Biscayne, Miami-Dade Police Detective Andre Martin said.

Key Biscayne police notified the Miami-Dade police homicide bureau, the agency that handles slayings in Key Biscayne, Martin said.

Personnel with the medical examiner’s office were investigating the cause of death, Martin said.

Police have not determined whether the person was killed in a slaying or whether a marine animal or a boating accident could have led to a decapitation, Martin said.

“We have not been able to determine exactly how the head became separated from the body, but there are a couple working theories,” Martin said.

No other human remains have been located, Martin said.

NBC South Florida reported that a person who was raking the beach made the discovery.

Aerial video showed investigators examining the remains as a section of the beach was closed off.