When employees of a Maine restaurant opened a huge wooden container, they believed it was a shipment of mugs they had recently bought.

Instead, they discovered a plastic tote containing 14 kilos (31 pounds) of the dangerous synthetic narcotic fentanyl, with an estimated street value of $3 million,  Auburn police Deputy Chief Timothy Cougle said in a statement Saturday.

The mailing label on the tote included the restaurant's address, but the name of someone who did not work there. Employees who opened it spotted what seemed to be narcotics and alerted police, according to Cougle.

The container from Arizona was transferred to the police department in the Maine town approximately 30 miles (50 kilometers) north of Portland, where a chemical field investigation revealed it contained fentanyl.

Police stated that about an hour later, the person whose name was on the cargo arrived seeking the container, and was detained.

Jeremy Mercier, 41, of Auburn, was arrested on narcotics charges and for breaking his release terms, and is being jailed without bond in a county prison. It was unclear whether he had an attorney.

Mercier previously served time in prison for a federal narcotics conviction in 2007, according to Cougle.

The inquiry is ongoing, and Cougle expects state and federal authorities to become involved.

In an email to WMTW-TV, Mike Peters, the co-owner of Mac's Grill, said he is relieved the drugs did not make it to the streets.

“The instances of overdose in our, and surrounding, communities is awful, and fentanyl seems to be front and center when it comes to fatalities,” he said. “It is very sad.”