Police say they have uncovered a massive heroin-selling operation behind a secret door that was disguised as a shelf at a New York City candy shop.

Police say State Finance Department officers discovered the door at the Gates Candy & Grocery store in Brooklyn on Wednesday during an inspection for untaxed cigarettes.

Police raided the store Thursday and say they found large quantities of drugs and drug paraphernalia. Police say they found bags of suspected heroin and barrels full of suspected fentanyl.

Fentanyl is a powerful prescription painkiller often cut with heroin.

The New York Post reports a 33-year-old Queens man and a 46-year-old Manhattan man face drug trafficking charges in connection with the operation.