A governor of Japan's public broadcaster, NHK, has denied that the Nanjing massacre took place, days after a row over Tokyo's use of war-time sex slaves engulfed the new NHK chief.

Naoki Hyakuta, a prominent novelist, made his comments as he campaigned for a right-wing candidate in the Tokyo gubernatorial election.

"In 1938, Chiang Kai-shek tried to publicize Japan's responsibility for the Nanking Massacre, but the nations of the world ignored him. Why? Because it never happened," the Asahi newspaper quote Hyakuta as saying.