Japan offered to donate 10 million Swiss francs under the name of the late Empress Kojun to the Geneva-based International Committee of the Red Cross during the last days of World War II and the money was secretly transferred in 1949 after a fierce battle over the fund, according to documents at the Swiss Archive Office and the ICRC archives.

The documents show that the United States and Britain claimed the fund was originally theirs, intended to assist their prisoners held by the Imperial Japanese Army, while Switzerland and the ICRC insisted the donation was valid and should be transferred to the ICRC.

Empress Kojun, who died last year at the age of 97, was the wife of the late Emperor Showa.

Japan's donation pledge for Sfr10 million in early August 1945 was earlier confirmed by official British documents. The new documents reveal the twists and turns of fighting among the three governments and the international organization, and how the unusually big donation was eventually made without Japan -- the donor -- being fully informed.