Guangzhou 2010 Asian Games taekwondo champion Wei Chen-yang was arrested for illegal drug possession.
The Taiwanese athlete also won two World Taekwondo Championships during his career,
Now 28, he was found in the possession of ketamine after being stopped at a random inspection checkpoint in September, Focus Taiwan reports.
Police then searched Wei's car and found a packet of drug-laced instant coffee.
It was allegedly the third time in the past year Wei had been caught in possession of an illegal substance.
It is likely his case will be handed over to prosecutors for further investigation.
Wei earned a gold medal for Chinese Taipei at the 2010 Asian Games, triumphing in the under-58 kilogram division, before claiming a bronze medal at Incheon 2014.
He also competed at the London 2012 Olympic Games, losing to Russia's Alexey Denisenko in the quarterfinal.
Wei achieved world bronze medals in 2011 and 2013.
It is reported that he has faced financial difficulties since retirement in 2014.