Photo/IllutrationThe headquarters of The Mainichi Shimbun newspaper in Tokyo’s Chiyoda Ward. (Asahi Shimbun file photo)

Envelopes containing a white powder believed to be deadly potassium cyanide and extortion letters threatening drug tampering have been received at six pharmaceutical companies and The Mainichi Shimbun newspaper office in Tokyo, police said Jan. 26.

The letters threaten to lace drug products with potassium cyanide unless money demands are met by Feb. 22.

Investigators at Tokyo’s Metropolitan Police Department are looking into the case as an extortion attempt by the same perpetrator on the grounds that the contents of the letters were the same.

Osaka and Hokkaido police also announced that a drug company in Osaka’s Chuo Ward and a leading Tokyo food company’s branch in Sapporo have received envelopes similar to those reported in Tokyo.

All those envelopes bore as the sender's name Shoko Asahara, the leader of the Aum Shinrikyo cult group who was executed in July, and other senior members of the cult group and leading members of a crime syndicate.

The Tokyo Detention House and prisons were written as the sender’s address on those envelopes. The powders were sent in plastic bags.

According to the metropolitan police department, the six drug companies and the daily newspaper’s headquarters office in Tokyo received the envelopes on Jan. 25. The postmarks suggested that they were all mailed in the capital.

Investigators said a screening test determined the powder to be potassium cyanide.

The letters, which are A-4 size, read: “Drugs laced with potassium cyanide will be distributed. Send Bitcoins worth 35 million won (3.4 million yen, or $31,000) by Feb. 22.” The text was printed.

The letter included a QR code to where the money should be deposited, but it turned out unreadable.

The Osaka prefectural police said the envelope sent to the Osaka drug maker was postmarked Jan. 24 and posted in Tokyo. The company reported it to police the following day.

Detailed testing determined that the powder was potassium cyanide.

Hokkaido police were alerted about the envelope by the food company’s branch office in Sapporo on Jan. 25. The powder was confirmed to be potassium cyanide during testing.

It said the envelope was mailed from outside Hokkaido.