A drug bust gone "fishy."

Police discover $100,000 worth of fentanyl inside raw fish.

Johnny de los Santos-Martinez was arrested after detectives found nearly nine pounds of the deadly opioid inside his car in the Bronx last week.

During a search, they discovered two Styrofoam coolers with fish wrapped around brick-shaped packages.

Each package consisted of one kilogram of fentanyl.

Altogether, the fentanyl could have yielded over a million lethal doses, with a street value of up to $10 million.

Santos-Martinez is being held on $150,000 bail.