Two fetuses were mailed to the Mütter Museum, without a return address. Police are investigating.

Mütter Museum curator Anna Dhody opened a package Tuesday morning that arrived at the museum by mail. Inside was a glass jar containing two preserved fetuses and a letter from someone claiming to be a retired physician who wanted to make a donation.

“I saw the letter and was like, ‘Oh no, no, no, I have to make a few calls,’” said Dhody, who promptly called the police. “This is not normal procedure.”

The package was addressed to Dhody but did not have a return address. The anonymous letter was scant and included no details about the sender or the fetuses, Dhody said.

Police are now investigating. The Philadelphia Medical Examiner’s Office retrieved the fetuses from the Mütter shortly after police responded to the call.

“There was no documentation regarding the specimens, there was no information about the mother or anything, or how the specimens came to be in the possession of the sender,” said Dhody.

Part of the College of Physicians of Philadelphia, the Mütter is renowned for its collection of anatomical specimens, including fetuses, skeletons, organs, and other human remains showcasing rare pathologies. While the medical history museum has previously accepted donations of human remains, procedures are in place for any new acquisition.

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“This is the first time human remains have just shown up on our doorstep,” said the curator, who has been at the Mütter for about 20 years.

The Mütter has received human remains in the mail before, when the donation was already approved and expected — such as the enlarged heart donated by Robert Pendarvis — but the museum does not accept unsolicited donations. In recent months, the Mütter has said that any donations of anatomical specimens are on hold as the organization crafts a new policy regarding its use and display of human remains.

Anyone with information about these remains can call Central Detectives at 215-686-3093, or call or text the PPD tipline at 215-686-TIPS (8477).