MIAMI -

An animal activist working several illegal horse slaughter investigations in Southwest Miami-Dade County made a gruesome discovery.

A human skull was found surrounded by animal remains in what appears to have been a sacrifice in a religious ritual.

Richard Couto of Animal Recovery Mission said he also found several human limbs.

Police have yet to confirm that they are human remains, but do say they are investigating.

Local 10's Christina Vazquez showed the pictures Couto took at the site to Aventura Police Officer Nelson Reyes.

Reyes came to Aventura with 20 years of experience at North Miami Beach, where he retired as a sergeant.

While at that department, he became an expert in Afro-Caribbean religions and teaches a course about the topic for the City of Miami's Police Academy.

Reyes says that when he sees strange images of dolls, animal parts, sticks and animal remains, he sees a mix of two different religions: Santeria and Palo Mayombe.

Palo Mayombe comes from the Congo and Reyes explained how people can be practitioners of both religions.

He said in one particular ritual that seeks to harness the spirit of a person, the human body parts would be found in between 21 sticks in a caldron. Which is exactly what Cuoto discovered.

The caldron was wrapped in a chain, which means they were trying to contain that spirit.

Reyes said the animals were sacrificed in order to "feed the spirit," which would be considered an entity.

He said this could be done for multiple reasons -- to either use the spirit as a sort of bodyguard to protect the practitioner, to release the spirit of a loved one, or ask the spirit to do some sort of bidding for them.

According to Reyes, in these religions "like produces like," so the body parts found help explain the kind of characteristics the person conducting the ceremony wanted that spirit to have.

So finding a tibia, for instance, would allow the spirit to be mobile, a skull with a decomposing brain inside would connote intelligence.

While the find may be disturbing, at this point it is unclear anything criminal happened.

Reyes said a Supreme Court ruling allows practitioners to conduct animal sacrifices and human bones can be found on eBay.

Miami-Dade Police and the State Attorney's Office will now have to investigate the origins of the human bones. They need to identify who the person was and where the bones came from.

Reyes said sometimes human bones are unlawfully dug up from cemeteries.

"After speaking with Homicide detectives, they advised that on Monday, April 9th at approx. 2:14  p.m. in the area of NW 170th Street & NW 107th Avenue, it appears that human bones were found (unknown amount).  Homicide detectives are working in conjunction with the Medical Examiner’s office," said Miami-Dade Police spokesman Javier Baez.

It is also unclear if the human bones found all belong to the same person or whether they are from different individuals.

Cuoto said law enforcement told him the site registered high levels of mercury. So much so that some people who handled the human bones got sick.

Reyes says the reason there might have been mercury on the site is because practitioners will often add quicksilver to speed-up the process. For example, if they are performing the ritual because they want help to close on a house and they need to close quickly because they need the money, quicksilver may be added during the sacrificial ceremony.