WICHITA, Kan. (AP) — Authorities say a Wichita, Kansas-area sheriff’s investigator was briefly hospitalized after being overcome with an unknown substance in a department evidence room.

The Sedgwick County Sheriff’s Department says the detective was processing evidence as part of a drug investigation when he opened a plastic bag and was overcome by a strong smell. The investigator then experienced sweating, slurred speech and dizziness.

The department says it’s unclear what the substance is and that it’s being tested. But the federal Drug Enforcement Administration has warned law enforcement agencies about fentanyl, a synthetic opioid said to be 50 times more powerful than heroin.