A record 400 kilograms of cocaine was seized by customs authorities in October at Kobe port, investigative sources said Thursday.

The latest seizure, with an estimated street value of ¥8 billion, more than doubles the previous record set when 177 kilograms were found at Mikawa port in Aichi Prefecture in August.

Local customs authorities and police believe someone tried to smuggle the cocaine from overseas by ship. The drug was found in shipping containers at the port, the sources said.

The smugglers may have sent the cocaine to Kobe by mistake, possibly intending to deliver it to another destination, the sources said without providing details.

According to Health, Labor and Welfare Ministry data, law enforcement authorities took action against 217 individuals last year in connection with cocaine-related charges, the highest number on record.

The ministry has acknowledged that the annual number of cocaine cases has been rising over the past several years.

Crime syndicate groups typically associated with the yakuza are said to profit from smuggling drugs, including cocaine.

Some celebrities in Japan have recently been convicted of using cocaine and other illegal drugs.

In June, the Tokyo District Court gave Pierre Taki, an actor and member of the techno-pop duo Denki Groove, 18 months in prison, suspended for three years, for using cocaine.