Based on a statement made by Representative Seijuro Arahune of the Japanese Diet in 1975 in which he claimed to cite numbers provided by Korean authorities during the 1965 Korea-Japan Treaty negotiations, as many as three-fourths of Korean comfort women may have died during the war, although the validity of this statement has since been brought into question as the number does not seem to be based on an actual investigation on the matter. Some sources further purport that most survivors were left infertile after the war, although it is unclear where this notion originated, as little in the way of a statistical study seems to have been conducted on the incidence of infertility among former comfort women.