Officials said the frames were in separate shipments that arrived last week in express air delivery at Philadelphia International Airport. Each shipment contained six picture frames.
They were shipped from the Netherlands and were headed to Hartford, Connecticut.
With assistance from CBP officers in Chicago, Philadelphia CBP officers inspected the packages.
According to CBP, officers discovered a white substance concealed in the plastic backing of the frames.
Officers tested the substance using a handheld chemical analyzer and identified the substance as ketamine.
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According to the Drug Enforcement Administration, ketamine is a club drug that delivers hallucinogenic effects and is sometimes used to facilitate sexual assault crimes. Ketamine can induce a state of sedation, immobility, relief from pain, and amnesia as the user may have no memory of events while under the influence.
CBP turned the picture frames and ketamine over to Homeland Security Investigations.
Special agents with Homeland Security Investigations arrested a man in Hartford.
The investigation is ongoing.