The North Korean man who was captured near the inter-Korean border last week was caught on South Korean military surveillance cameras ten times but soldiers still failed to notice him.
According to South Korea's Joint Chiefs of Staff, the man reached the shore near the Unification Observatory in Goseong at around 1:05AM last Tuesday.
He then passed through a hidden drainage tunnel under the heavily fortified border fence.
At around 1:40 AM the man started moving south going some five kilometers along the country's east coast.
He did all this undetected until at around 4:12AM one of the military's CCTV cameras spotted him and again at around 4:16AM he was seen by a guard at the Civilian Control Line through CCTV some 330 meters north of the Jejin checkpoint.
The man was spotted once again at around 4:18AM going eastwards over the guardrails towards the sea.
After a three-hour manhunt, the man was finally captured by the military at around 7:27AM.
The Joint Chiefs said the man swam from North Korea towards the South.
It revealed that he is presumed to have been wearing a thick padded coat inside the diving suit, which covered his whole body except for his face.
The military unit was unaware of the presence of the drainage tunnel that's now presumed to have been used by the intruder.
"The Joint Chiefs of Staff will conduct a comprehensive investigation of the waterways under the border's barbed-wire fences and come up with follow-up measures. It'll also seek improvements in the operation of the border's surveillance system."
The military also found fault in the unit for failing to take appropriate action after the alert systems had detected human movement.
Kim Ji-yeon, Arirang News.