NEW YORK (CBSNewYork) — The NYPD found no criminality after officers became sick at a Shake Shack in downtown Manhattan, Chief of Detectives Rodney Harrison tweeted early Tuesday.

Sources told CBS2 it appears the incident was accidental, possibly the result of cleaning solution that wasn’t properly removed from the shake machine.

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Three officers became sick Monday after drinking shakes from the restaurant located at Broadway and Fulton Street.

Police initially suspected an employee may have contaminated the shakes with bleach.

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Employees were questioned, and a shake sample was taken to a lab for testing.

The officers were hospitalized, but have since been released.

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Note: This post was updated at 4:30 a.m. on June 16, 2020.