Police and customs served new arrest warrants Tuesday on three people, accusing them of smuggling 143 kg of stimulant drugs disguised as floor wax into the country through Yokohama in April.
Food broker Cao Zhisen, 55, a Chinese national; Au Sin Hong Stanley, 38, a trading company head and British national from Hong Kong; and his Japanese wife Junko Kikkawa, 38, smuggled the amphetamines in plastic bottles purported to contain floor wax, according to joint investigations by police and customs.
The three had dissolved some of the amphetamines in 120 liters of water, put it into 96 bottles and smuggled it into Japan on April 24 at a wharf in Honmoku, Yokohama, according to the arrest warrants.
Cao admitted to the charge while the others told investigators they were asked by Cao to import the bottles and did not know they contained illegal drugs, authorities said.
The police said they are questioning the three about the similar smuggling of 187 kg of amphetamines on three occasions since last November.
The three have been detained since May 8, when they were arrested on suspicion of possessing amphetamines in another 96 plastic bottles at a Tokyo office owned by Au and others.
But prosecutors suspended investigations on the illegal possession of the drug before their 23-day detention expired, indicating they are unlikely to be indicted on that charge.
The police instead served fresh warrants after the prosecutors' decision, accusing the three of drug smuggling.