Extortion letters with cyanide powder sent from central Tokyo post office on Jan. 24

TOKYO -- Envelopes containing deadly potassium cyanide powder sent to 18 companies across Japan were all posted by noon on Jan. 24 from central Tokyo, a person close to the investigation has told the Mainichi Shimbun.

It has now been one week since the envelopes, which also contained notes demanding a ransom, first appeared. The Metropolitan Police Department (MPD) has set up a dedicated investigative team of 75 officers to probe the attempted extortion scheme and identify the culprit.

Targeted corporations include 11 pharmaceutical firms and one food company in Tokyo, three drug companies in Osaka Prefecture, western Japan, and a food company in Sapporo, capital of the northernmost prefecture of Hokkaido. Envelopes were also sent to the Tokyo head offices of the Asahi Shimbun national daily and The Mainichi Newspapers.

According to an individual close to the case, all 18 envelopes were postmarked from the Kanda Post Office in Tokyo's Chiyoda Ward. The postmark indicates that most of the letters were sent between 8 a.m. and noon on Jan. 24. The postmark stamp is apparently too blurred to read on the remaining envelopes.

According to Japan Post Co., the Kanda postmark is stamped on all mail sent from the Kanda Post Office and from the some 170 postboxes in the office's area of responsibility. MPD investigators are examining surveillance camera footage from around the area's postboxes.

The extortion notes sent to the pharmaceutical firms threatened to "distribute fake drugs containing potassium cyanide" if the companies did not wire 35 million won in Bitcoin (electronic money) by Feb. 22. "If you don't send the money, there will be a tragedy," the notes stated. The notes sent to the drug companies in Tokyo and Osaka also included QR codes, but they were apparently unreadable.

The letters made the demands under the name "Shoko Asahara" and other leading members of AUM Shinrikyo, the cult behind the March 1995 sarin gas attack on the Tokyo subway. Sender addresses included that of the Tokyo Detention Center. All the notes were apparently written on a computer, and some of the characters were non-standard kanji.

According to the MPD, similar notes under the names of senior yakuza gangsters and other figures were sent to pharmaceutical companies in January 2018. However, the envelopes in that case did not contain any powder. The current batch of extortion letters warn that "this is the last warning," and police believe the same person is behind both incidents.

(Japanese original by Takayuki Kanamori and Shota Harumashi, City News Department)