Updated at 2:05 a.m. ET

A Milwaukee pharmacist was arrested Thursday and accused of "tampering with and causing the destruction" of more than 550 doses of the Moderna vaccine against the coronavirus last week, Grafton, Wis., police confirmed.

In a statement, Grafton Police Department officials said the pharmacist — now fired from the Advocate Aurora Health hospital system — was arrested on recommended charges of first-degree recklessly endangering safety, adulterating a prescription drug and criminal damage to property.

Officials did not release the individual's identity "pending formal advisement of charges." However, a licensed pharmacist named Steven Brandenburg was booked Thursday for the same charges, according to the Ozaukee County Sheriff's Department.

Officials said that in a written statement to Aurora Health public safety officials, the pharmacist responsible admitted "to intentionally removing the vaccine knowing that if not properly stored the vaccine would be ineffective."

The Moderna vials must be stored between 36 to 46 degrees Fahrenheit. They can remain effective for up to 12 hours if left at room temperature. Beyond that, the drug is rendered useless.

During a teleconference Thursday, Chief Aurora Medical Group Officer Jeff Bahr told reporters that the former employee deliberately removed the vials from refrigeration on two separate occasions — on Dec. 24 overnight, then returning them to proper storage, and then again on Dec. 25 into Saturday morning.

A pharmacy technician discovered them outside the refrigerator on Christmas morning and immediately notified superiors, Bahr said.

As a result, health care workers were forced to throw out about 570 doses of vaccine. However, some people were given the medicine that had been left out.

Grafton police detectives reported 57 patients received those injections. Bahr said those vaccines were rendered potentially less effective or altogether ineffective. The patients, who have been notified, are not at any risk of adverse health effects because the doses were left out, he noted.

The pharmacist told investigators he knew "that people who received the vaccinations would think they had been vaccinated against the virus when in fact they were not," officials said.

The value of the spoiled doses is estimated to be between $8,000 and $11,000.

The suspect is currently being held in the Ozaukee County jail.

NPR's breaking news reporter Jaclyn Diaz contributed to this report.

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