Photo/Illutration Tokyo Port on June 1 (Ryo Oyama)

Police have arrested seven Chinese nationals in connection with around 700 kilograms of methamphetamine smuggled into Tokyo Port, the second-largest drug seizure in the country, investigative sources said on June 7.

The stimulants, detected during a customs inspection, have an estimated street value of around 43.4 billion yen ($312 million), the sources said.

The drugs were concealed in seven containers on a cargo ship that arrived at Tokyo Port in early March. The ship had traveled from Dubai in the United Arab Emirates via Ningbo, China.

Investigative authorities had obtained information that a Chinese group was smuggling drugs into Tokyo Port, the sources said.

Police let the group move the containers from Tokyo Port to a warehouse in Kawaguchi, Saitama Prefecture, and a facility in Noda, Chiba Prefecture, the sources said.

In April, when the group was moving the containers again, police arrested two Chinese nationals on suspicion of violating the narcotics special case law. Three others were later arrested on the same allegations.

After that, three of the five suspects were re-arrested on suspicion of violating the Stimulants Control Law.

On June 6, two additional Chinese nationals were arrested over suspected violations of the narcotics special case law.

The suspects were in their 20s to 50s. Three of them had been released from custody by June 7.

The 700 kg of methamphetamine exceeded the total amount seized nationwide for all of 2022.

It is the largest amount detected through a customs inspection, according to the Finance Ministry.

The amount is the second-largest drug seizure in Japan. The biggest haul was one ton of drugs found on a vessel in Shizuoka Prefecture in 2019.

Police plan to continue investigating the case, suspecting an international smuggling group was involved.

According to ministry statistics, annual seizures of methamphetamine smuggled by aircraft or ship into Japan have been declining in size since peaking at 2,587 kg in 2019.

In 2022, when strict border restrictions were in place for the COVID-19 pandemic, the total amount seized was around 567 kg.

“Smuggling may further increase with the relaxation of the restrictions,” a senior investigator said.

(This article was written by Shoko Mifune and Ryo Oyama.)