Visiting Mongolian President Natsagiin Bagabandi on Thursday handed over documents on about 110 Japanese transferred to Mongolia after being detained by the Soviet Union after World War II.
Bagabandi submitted the names and general background of the internees when he met with Prime Minister Junichiro Koizumi.
The Foreign Ministry plans to hand over the documents to the health ministry, which is in charge of internees from the war, and provide the information to their families, a Japanese official said.
It is estimated that the Soviet army detained about 575,000 Japanese after the war in various places, including northeastern China. About 10,000 Japanese are believed to have been moved to Mongolia, and Japan is trying to determine what became of them.
In 1991, then Prime Minister Toshiki Kaifu asked Mongolia to gather a list of information and submit it to Japan.