Traces of toxic chemicals have been found at a US military camp but there is no evidence yet to support claims that Agent Orange was buried there in 1978, South Korean and American investigators said Friday.

Dangerous levels of trichloroethylene and tetrachloroethylene were detected in underground waters at Camp Caroll near the southeastern city of Daegu, the joint team said in a statement.

Trichloroethylene is commonly used as an industrial solvent and tetrachloroethylene is used for dry cleaning of fabrics.

The team has been investigating allegations that large amounts of Agent Orange were dumped and buried at the US logistics base in 1978.

"These pollutants are not associated with Agent Orange. There is no clear indication of where these pollutants originated," the statement said.

The investigators also said they had begun collecting earth samples from 43 different sites at the base, including one where a US veteran said 250 barrels containing the toxic defoliant were buried.

The team's findings will be made public near the end of August, they said.

Following the US veterans' claim made on American television, the US military in Korea said in May that a "large number" of drums containing pesticides, herbicides and solvents were buried there in 1978.

But it said there was no specific information that Agent Orange was in the containers. It said the materials along with 40-60 tonnes of soil were removed from the site in 1979-1980 and disposed of elsewhere.

The US has based tens of thousands of service personnel in the South since the 1950-1953 Korean War, with 28,500 troops currently stationed in the country.

During the Vietnam War US aircraft sprayed Agent Orange and other herbicides containing potentially cancer-causing dioxin to strip trees of foliage, in a bid to deprive communist forces of cover and food.