MARTIN COUNTY — A man told deputies he had nothing hidden on him, but guess what they plucked from beneath his private parts?

A sack of the powerful opioid fentanyl, records show.

The case of the man with painkillers under his privates happened Oct. 10 in Stuart, according to an arrest affidavit.

Martin County sheriff’s officials reported stopping a vehicle on Southwest Kanner Highway after noticing the driver, later identified as Giuliano Olivieri, 28, wasn’t wearing a seatbelt.

More: Why is a naked man in my home?

Investigators said Olivieri and a passenger were “moving around in a frantic manner.”

Olivieri was shaking, his forehead “sweating profusely.” Investigators reported his license was suspended, and took him into custody.

Olivieri was brought to the county jail. On the way, a deputy said if he had any contraband on him he should disclose it.

More: Woman jailed after beer runs dry, hits hubby

Olivieri said he had nothing, but officials at the jail apparently were on the ball. They reported finding a plastic baggy with half a dozen capsules of fentanyl “underneath his (private parts).”

Olivieri, of Port St. Lucie, was arrested on charges including knowingly driving while license suspended, possession of controlled substance and introduction of contraband into correctional facility.

More: PSL man busted in lo mein melee

Meanwhile, investigators said a woman, identified as Argelia Torres-Rojas, 33, also was in the vehicle. In her purse, investigators found two used syringes, an affidavit states.

Torres-Rojas said someone must have put them there without her knowledge.

Torres-Rojas, of Okeechobee, was arrested on a charge of possession of drug paraphernalia.

More: Man in undies hangs with pot on highway, according to report