The leader of a Japanese nongovernmental organization being held by Chinese authorities in Shanghai called on Japanese Consulate officials Tuesday to urge Beijing not to repatriate the North Koreans who were detained with him, Japanese officials said.

Fumiaki Yamada, 54, leader of the Tokyo-based Society to Help Returnees to North Korea and an assistant professor at Osaka University of Economics, was taken into custody and is being questioned for allegedly helping North Koreans enter China illegally. Consulate officials were allowed access to him Tuesday afternoon.

According to Foreign Ministry officials, Yamada told the consulate staff that the North Koreans who were detained with him were all relatives of North Koreans who left Japan under a 1959-1984 repatriation program, and that they could be executed if they are repatriated. He asked the officials to work with the South Korean government to call on China to consider the matter from a humanitarian viewpoint, they said.