A screen capture from a video posted on Instagram shows a man in Suwon, Gyeonggi Province, on June 21. Police said Monday that a conclusive forensic test found no traces of illegal drugs in his urine. (Instagram) A man who was detained on suspicion of drug use after a video of him behaving unusually in Suwon went viral has tested negative in a conclusive forensic drug test.Urine tests conducted by the National Forensic Service found no traces of illegal drugs in the man’s system, according to the Suwon Gwonseon Police Station on Monday. He was arrested June 23 on suspicion of drug use after a rapid drug test came back positive for methamphetamine.The investigation began after a video of the man circulated widely on social media. In the video, he was seen standing limply for some time with his shoulders hunched and both arms hanging down. He told police he had been acting unusually because he was tired and was stretching his limbs.Police released him Wednesday after a preliminary NFS test came back negative. A confirmatory test, which usually takes about a week, also came back negative. Investigators have yet to find any other evidence suggesting drug use.Police are now looking into why the initial rapid test produced what is believed to have been a false positive. They have also asked the NFS to analyze the man’s hair to determine whether he used drugs in recent months.Hair follicle drug testing generally takes about a week, although it can take longer in some cases. The result is expected to determine whether police close the investigation.