Classified ministry documents were leaked to the head of a Japanese export-promotion group who spoke often with a Chinese diplomat suspected of spying, according to new farm minister Akira Gunji.

"I've heard that several kinds of documents were leaked" to the head of the Tokyo-based Promotion Association of Agriculture, Forestry, Fisheries & Foods Exporting to China, Gunji told Japanese media Wednesday. "I've told ministry officials to investigate the matter thoroughly to report our findings properly."

The head of that group had frequent contact with Li Chunguang, a first secretary at the Chinese Embassy in Tokyo suspected of engaging in espionage while in Japan. Li has returned to China.