Korea Times file

A North Korean man was caught on military surveillance cameras along the east coast 10 times after he swam ashore in the South last week, but soldiers did nothing to stop him even after alarm bells rang, the Joint Chiefs of Staff (JCS) said Tuesday.

The announcement was a key point of the results of the JCS' weeklong probe into the Feb. 16 incident. The North Korean man was ultimately captured more than six hours later inside a restricted area north of the Civilian Control Line in the eastern border town of Goseong.

He has expressed his desire to defect.

According to the probe, the man is believed to have swum in the East Sea overnight wearing a hard-hat diving suit. Upon arrival near an observatory in the South at around 1:05 a.m., he passed through a drainage conduit beneath the barbed wire fences set up along the shore.

He then moved along the street undetected until around 4:16 a.m., when guard soldiers found him through a CCTV camera and reported the case to his superiors. After a three-hour manhunt, the military took him into custody at around 7:27 a.m.

After arriving at the coast, the man was caught on the coastal surveillance cameras five times between 1:05 and 1:38 a.m., and the system rang an alarm twice. But guard soldiers missed those signs and no actions were taken.

At around 4 a.m., military CCTVs set up along ground fences also caught the man three times, but no warning bell rang, allowing the man to continue to move south.

"Service members in charge of the guard duty failed to abide by due procedures and failed to detect the unidentified man," the JCS said in a release.

The drainage conduit the man passed through also had not been checked, as the military had not even been aware of its existence.

In July last year, the authorities ordered all coast guard units to check on barriers inside drainage tunnels after a North Korean defector returned to the North by passing through such a waterway on the western border. The check was supposed to be done by August.

"Over the course of the investigation, we've found three drainage tunnels which are not on our list," the JCS said. "The tunnel he went through was believed to have been damaged even before his passage."

In the wake of the security lapse, the JCS vowed to strive to tighten discipline and supplement the surveillance system along the border.

The military has come under fire for a series of security breach cases. In November, a North Korean civilian was captured hours after he crossed the inter-Korean border by jumping over barbed wire fences in Goseong in a suspected defection attempt.

In 2019, a wooden boat carrying four North Koreans arrived at an eastern South Korean port undetected. (Yonhap)