TOKYO - A Japanese Government team has found documents on an alleged secret pact with the United States to transport nuclear weapons through its territory, after decades of official denial.

Prime Minister Yukio Hatoyama's centre-left Government launched a probe into the alleged nuclear pact and other secret agreements with the US days after it took office in September.

The probe team reported to Foreign Minister Katsuya Okada that it had discovered documents linked to the pact from among thousands of files at the Foreign Ministry, the Mainichi Shimbun and Yomiuri Shimbun newspapers reported, citing unnamed ministry sources.

"Foreign Minister admits 'nuclear secret pact"' declared the headline in the Mainichi, while the Yomiuri echoed: "Government view likely to change - 'nuclear secret pact"'.

The existence of the agreement has been denied for decades by previous conservative Administrations, even though US documents declassified last month showed US officials believed they had an understanding with Japan when the allies signed a new security treaty in 1960.

"The question of black or white will become clear in January. We will clear the burden of previous Administrations which had insisted there was no secret pact," Okada said.

The papers said the minister would set up a committee of experts to examine the documents before announcing the Government's final judgment in January of whether the secret pact did indeed exist.

Japan, the only nation to have suffered nuclear attacks and which has campaigned for the worldwide abolition of the weapons, has had a policy of not possessing, producing or allowing nuclear arms on its territory since 1967.

But the confidential US State Department memo prepared in 1960 said the US could use Japanese soil "as needed" in an emergency if communist neighbour North Korea attacked.

- AFP