A key component of Agent Orange has been detected for the first time in groundwater samples near Camp Carroll, in Chilgok, some 300 kilometers southeast of Seoul.

The South Korea-U.S. joint probe team said Friday in the third interim report of its investigation that it detected zero-point-161 parts per microgram of 2,4,5-T in groundwater extracted from Area 41 in the military base, where the defoliant had first been stored.

Two other groundwater samples taken outside Camp Carroll each tested positive once for traces of 2,4-D, another key component of Agent Orange, and 2,4,5-T during two rounds of testing.

The joint probe team will also test more soil samples from Area 41 and soil samples from beneath the base's helicopter pad as soon as possible.