CLAREMONT, N.C. (AP) — A field of poppy plants that could be used to make opium was discovered in North Carolina and had an estimated value of $500 million, a sheriff says.

Catawba County Sheriff Coy Reid said the only other opium poppy plant field found in the U.S. this year was in California.

The acre (nearly half a hectare) of poppy plants were in rows, similar to how corn would be planted, in a field behind a home.

"One of our narcotics investigators came to the house looking for something else. When he knocked on the door, the guys said 'I guess you're here about the opium,'" the sheriff said.

The sheriff's office says Cody Xiong was arrested and charged with manufacture and trafficking by possession. It's unclear if he has a lawyer.

Officials don't think opium was being made on the property.

"The plants are being harvested here, and sent somewhere else where the opium is being produced from the plant," Capt. Jason Reid said told WBTV.