Japan said Friday it was withholding financial contributions to UNESCO to express its outrage with the UN cultural body for listing Chinese documents relating to the 1937 Nanjing Massacre in its "Memory of the World" programme, according to local media.
Japan's Foreign Minister Fumio Kishida said the government was withholding this year's contribution of 4.4 billion yen (42 million dollars), according to Japanese news agency Kyodo.
Tokyo has claimed UNESCO registered the documents without allowing the government to access them for verification.
Japan disputes the number of Chinese civilians and soldiers killed in the massacre by the invading Imperial Japanese Army.
The Chinese documents were submitted to UNESCO by China in 2014 and were included in the heritage list last October, Kyodo reported.
UNESCO's "Memory of the World" programme calls for the preservation of valuable documents which relate to significant historical and cultural events.
Prime Minster Shinzo Abe's government has denied Beijing's claims that over 300,000 people were killed, citing historians' estimates that range from tens-of-thousands to 200,000.