'My body just felt weak,' says man released after negative drug test in Suwon 'zombie' drug scare

A man in his 30s who was arrested on suspicion of using fentanyl — dubbed a "zombie drug" — has been released after an initial forensic test came back negative.

The Suwon Gwonseon Police Station in Gyeonggi Province said Wednesday it had released the man, identified only by the initial A, after the National Forensic Service returned a negative result on a preliminary examination.

A was first spotted Sunday around 12:30 p.m. near a bus stop outside an apartment complex in Gwonseon-gu, Suwon, hunched over with both arms hanging limply at his sides for an extended period.

A citizen who filmed the scene posted the video on social media Monday under titles including "Suwon fentanyl today," and it spread rapidly online.

Police became aware of the incident Tuesday around 7 a.m. and analyzed nearby CCTV footage to identify A based on his physical description.

A field drug test returned a positive result for methamphetamine, and police arrested him around 10:30 a.m. No drugs were found on him at the time of his arrest.

The more detailed forensic examination reversed that finding. A tested negative not only for methamphetamine but also on a fentanyl screening kit. "A has not tested positive for methamphetamine or any other drug," a police official told Yonhap News Agency.

A denied the charges during police questioning, saying he had been standing that way because he simply felt weak at the time.

Police released A while awaiting the National Forensic Service's final results, which are expected to take about a week. They said they will determine the next steps in the investigation based on those findings.

Fentanyl is a highly addictive synthetic opioid known in the United States and elsewhere as a "zombie drug." In the United States, fentanyl-related overdose deaths number around 100,000 each year.