A Japanese narcotics firm in wartime occupied China sold enough opium to nearly match the annual budget of Tokyo's puppet government in Nanjing, according to an internal company document recently discovered by The Japan Times.

The 21-page document, found in an archive at the National Diet Library of Tokyo, showed opium dealer Hung Chi Shan Tang (or Hong Ji Shan Tang as it would now be spelled) sold as much as 300 million yuan worth of opium in 1941, when the annual budget of the Nanjing Government was 370 million yuan.

Although not widely known at home, Japan's opium trade in China was considered an essential financial resource for the Imperial Japanese Army and Japan's puppet governments.