Prime Minister Taro Aso admitted Tuesday that the Foreign Ministry deleted a written protest to The New York Times from its Web site last month after finding evidence that a company run by his family during World War II used Allied POWs to work its coal mines.

In 2006, the International Herald Tribune, published by The New York Times, printed a story that said Aso Mining Co. used Asians and Westerners as forced laborers. Aso was foreign minister at the time the story was published.

"Last year, the health ministry's investigation newly revealed that Allied POWs did work at Aso Mining," Aso told a Diet session Tuesday. "I believe that the Foreign Ministry deleted the counterargument from the Web site because new facts that were not acknowledged at the time of publication have been ascertained."

He did not elaborate further.

The Foreign Ministry had argued on the Web site of the Consulate General of Japan in New York that the "government has not received any information the company has used forced laborers" and that it was "totally unreasonable to make this kind of judgmental description without presenting any evidence."

But last month, the government deleted the protest after the health ministry revealed it found old documents showing Aso Mining Co. in Fukuoka Prefecture used 300 Allied POWs, of which 101 were Britons, two were Dutch and 197 were Australians. Whether the POWs were mistreated could not be ascertained via the documents.