Japan has placed under its protective custody dozens of people who have fled North Korea, including Japanese spouses of Koreans and former Korean residents of Japan, a senior Foreign Ministry official told the Diet on Monday.

Asked about reports of such clandestine activities that also involve China, Mitoji Yabunaka, the director general of the ministry's Asian and Oceanian Affairs Bureau, told the House of Representatives Budget Committee "there have been dozens" of cases.

It is the first time a government official has formally acknowledged that Japan has protected such people.