PHILADELPHIA (CBS) — Philadelphia police have launched an investigation after they said a package containing two preserved fetuses was delivered to the Mütter Museum Tuesday morning. 

Police said at around 11:36 a.m., museum staff received a package that held two preserved fetuses inside a glass jar. It is unknown at this time where the package came from. 

“I opened it up. There was a letter there that said this was a retired physician and he or she was saying they had these two specimens and that’s basically it,” Museum curator Anna Dhody said.

Dhody said when it comes to donations, there’s a whole process that goes into it and nothing is ever just dropped off at the museum like this. She said the package was specifically addressed to her and didn’t include a return address.

“But there was no identifying information. They just identified themselves as a retired physician. There were two bottles with fluid and inside that there appeared to be two very small fetal remains,” she said. 

The fetuses are said to have been turned over to the Philadelphia Medical Examiner’s Office for review.

Philadelphia’s Mütter Museum displays preserved collections of anatomical specimens, models and medical instruments.

The goal of the unique museum is to help its visitors understand the mysteries and beauty of the human body and appreciate the history of diagnosis and treatment of disease, the Mütter website said. 

Anyone with information regarding the unusual incident is asked to call or text the Philadelphia Police Department tip line at 215-686-TIPS (8477).