The chief of the U.S. Defense Technology Security Administration has questioned South Korea on an attempt to steal the technology behind the AN/AAS-42 Tiger Eyes IRST on board the F-15K.
The Pentagon found one system had its seals broken when it was returned to the U.S. for maintenance.
There were signs that the set had been disassembled and put back together. However, a weeklong joint investigation from Sept. 18 found no evidence of tempering.