LEONIA, NJ (PIX11) — A bag containing what appears to be a human placenta and fetal membranes was pulled from the water of a New Jersey park on Wednesday officials said.

The Bergen County Sheriff’s Office responded to Overpeck County Park after someone pulled the bag from the lake. The county Medical Examiner’s Office is determining the exact contents of the bag.

The Bergen County Prosecutor’s Office is working with the Sheriff’s Office on the investigation. Officials have not released additional details.