On Monday, the court said that it was difficult to confirm whether a liquid sample taken from Aska, 58, that tested positive for kakuseizai, or stimulant drugs, was urine that actually came from the musician himself.
On November 28, Aska, who is on parole for drug violations, placed an incoherent call to police from his residence in Meguro Ward.
A urine sample subsequently taken from the musician tested positive. The musician, whose real name is Shigeaki Miyazaki, was later arrested for violations under the Stimulants Control Law.
Aska provided what was then considered a urine sample while he was inside a bathroom at his residence. However, it was later learned that police officers did not monitor the musician during the entire sampling process.
Aska was released from custody at the Tokyo Wangan Police Station on Monday evening.
After news of the incident surfaced, Aska offered a denial on his blog, claiming it was “a mistake” and that “there was no problem.” On Monday, he updated the blog to indicate that the charges had been dropped.
In September of 2014, the Tokyo District Court handed Aska, 57, whose real name is Shigeaki Miyazaki, a suspended three-year prison sentence for possession and use of stimulant drugs. He had been arrested in May of that year.