The head of the pro-Pyongyang General Association of Korean Residents in Japan, or Chongryon, had his home searched by police on Thursday, and two South Korean men were arrested on suspicion of illegally importing matsutake mushrooms from North Korea.
Raids took place at six locations, including the Tokyo home of Ho Jong Man, chairman of Chongryon, a body which has functioned as a de facto North Korean embassy for many decades in the absence of diplomatic ties between Tokyo and Pyongyang.
Observers said the raid on the chairman's home could affect stalled bilateral talks on Pyongyang's abductions of Japanese nationals in the 1970s and 1980s.