In the late 1960s, the U.S. military buried dozens of barrels of the toxic defoliant Agent Orange in an area around the town of Chatan on Okinawa Island, an American veteran has told The Japan Times.

The former serviceman's claim comes only days after Foreign Minister Takeaki Matsumoto said that he would ask the U.S. Department of Defense to come clean on its use of the chemical on the island during its 27-year occupation of Okinawa between 1945 and 1972. The U.S. government has repeatedly maintained that it has no records pertaining to the use of Agent Orange in Okinawa.

The veteran's allegation is likely to cause considerable concern in Okinawa, as Agent Orange contains highly carcinogenic dioxin that can remain in the soil and water for decades. The area where the veteran claims the barrels were buried is near a popular tourist and housing area.