SEOUL, (Yonhap) -- The U.S. military in South Korea will use ground-penetrating radar devices next week for tests of soil on one of its bases in the South where large amounts of the toxic chemical Agent Orange were said to have been illegally buried in the 1970s, the chief investigator in the claims said Thursday.

South Korea and the U.S. launched a joint probe last week following the allegations by American veterans that U.S. Forces Korea (USFK) buried the dangerous chemical near a heliport inside Camp Carroll in 1978.

"As early as next week, we will have ground-penetrating radars that we can put over the location, and we will be able to see anything else buried there," the lead investigator, Eighth U.S. Army commander Lt. Gen. John D. Johnson, told a local radio station.

"And then if there is any indication of a threat to human health and there will be a test of soil," Johnson said.

Early this week, the USFK said a large number of drums containing pesticides, herbicides and solvents were buried in 1978 at Camp Carroll in Chilgok, 300 kilometers southeast of Seoul, but they were removed during the following two years.

The USFK also said its review of military records showed that "trace amounts" of dioxin were found in 2004 ground testing at the site, but the findings have not "directly" indicated that Agent Orange was buried at Camp Carroll.

Agent Orange, a powerful toxic herbicide that was widely used in the Vietnam War, is suspected of causing serious health problems, including cancer and genetic damage in some people exposed to it and birth defects in their offspring. The defoliant was contaminated by dioxin, a highly toxic substance.

Environmental contamination at U.S. bases has been a source of friction between South Korea and the U.S. in the past.

While senior U.S. officials in South Korea, including USFK commander Gen. Walter Sharp, have pledged a "swift and transparent" probe into the allegations, impatience among South Koreans is growing because the USFK has failed to determine why the chemicals were buried or where they were moved to.

"I don't have a complete answer yet," Johnson said, when asked about whether the chemicals were relocated to inside South Korea or moved abroad.

Johnson acknowledged that the U.S. military had moved Agent Orange in Vietnam to a "special island" for disposal.

Some 28,500 American service members are currently stationed in the country, a legacy of the 1950-53 Korean War. About 3,800 people work at Camp Carroll, and 900 U.S. soldiers live there, according to USFK officials.