The Ministry of Foreign Affairs responded to the Japanese police's arrest of a researcher of Chinese nationality: it has expressed its concern to the Japanese side through diplomatic channels. Caihui, 19 Jun (Xinhua)-- Foreign Ministry spokesman Mao Ning held a regular press conference on 19 June. A reporter asked about the arrest of a Chinese researcher by the Japanese police. Spokesman Mao Ning said that the Chinese side has taken note of the relevant reports and is highly concerned about this. We have expressed serious concern to the Japanese side through diplomatic channels, demanding that the Japanese side earnestly safeguard the legitimate rights and interests of Chinese citizens, and hope that the Japanese side will earnestly respect the legal system, market economy and the principle of fair competition, so as to create a good environment for Sino-Japanese scientific and technological exchanges and cooperation.