Experts said Chinese laborers coerced to work in Japan during the World War II were far in excess of 40,000, contradicting claims made in a highly-publicized list last week.
They also dismissed claims that the document was the first time the number had been "revealed to the public."
Experts believe the real number far exceeds 40,000 even though the list gave the number, names and birthplaces of laborers in detail.
Li Zongyuan, a scholar in the field, said the list was made by the Foreign Affairs Department of Japan in 1946 after Japan lost the war.
The department collected figures sent by 135 workshops under 55 enterprises that used Chinese laborers and wrote the report, but the report was not publicized until some Japanese found it in June 1964.
"Quite a few scholars conducting research in the same field as I do saw this document long ago," he said.
"We found this document does not reflect the true situation at that time."
Earlier last week, some Chinese media reported that the list and related materials donated by Japanese friends in December revealed for the first time that 38,935 Chinese laborers - most of them in their 20s - were taken by force to work as coolies in Japan's 135 mines from April to November 1943 and March 1944 to May 1945.
Li added: "We should not draw any conclusions on the exact figure before we have all the facts."
Some survivors among the laborers did not even find their names on this list, and this proves it cannot be accurate, said Li who is currently immersed in a two-year research project with Japanese scholars.
Many enterprises failed to give the right number by only counting the numbers of the dead and even missing some names on purpose. Those who died on the way from China to Japan were often disregarded, he said.
The Japanese built large concentration camps in North China from 1943 to 1945, where Chinese laborers stayed before being sent to Japan to produce wartime materials to realize its expansion ambitions.
Li talked to a survivor who successfully fled from a concentration camp in Shijiazhuang, capital of North China's Hebei Province. He was told almost 20 to 30 Chinese died every day in his camp before being sent to Japan to work.
And this death rate was possibly even higher during the 169 transportation trips made between China and Japan, when the living conditions on board the ships were miserable.
(China Daily January 14, 2002)
