Messing-Mierzejewski’s records from his position as the Outposted Officer in South East Asia from 1963 to 1965 include reports addressed to the Director of the Division of Narcotic Drugs. There is also correspondence exchanged between Messing-Mierzejewski, the Director of the Division of Narcotic Drugs, Thai officials, and representatives of organizations and Member States working in South East Asia on narcotics control. The records contain surveys with information about the opium-growing hill tribes of Thailand, visits to South East Asian countries and diplomats, and rehabilitation options for individuals afflicted with narcotics addiction in South East Asian countries.