A Vermont state trooper received three doses of the opiate-reversal drug Narcan after being exposed to an unknown substance.

It happened late Friday night and into Saturday morning after a traffic stop on Whiting Road in Leicester.

Authorities say that while speaking with the driver, Vermont State Police Sgt. Brett Flansburg noticed the passenger, Taylor Woodward, 25, of Brandon, swallowed what was later identified as a baggie of cocaine.

After a search of the car and Woodward, a small amount of heroin, an empty plastic bag and a syringe were found. Woodward was arrested on suspicion of possessing heroin.

When Flansburg returned to the barracks, he collapsed in the parking lot. Troopers found him unconscious and administered two doses of Narcan, and a third dose was administered on the way to the UVM Medical Center. Flansburg was eventually released and is recovering.

Woodward was brought separately to UVMMC and required no medical care.

Vermont State Police Lt. Maurice Lamothe assisted at the hospital and says he's never seen an incident like this involving an officer.

"He was as safe as he could be. But there is always a chance that, despite everything that you do to be safe, that there's always the chance that something like this could happen. So we're looking at to see exactly how it occurred and hopefully we can prevent something like this from happening in the future," Lamothe said.

Police are testing the substance to determine what Flansburg was exposed to. A full investigation of the incident is underway.