Two North Korean fishermen, who allegedly murdered 16 fellow crew members before being captured by a South Korean naval unit, have been returned to North Korea, South Korean media reported on Thursday afternoon.

The two apparently carried out the bloody act aboard a squid fishing vessel in waters off the peninsula’s east coast, South Korean TV news reports said. They were picked up by the South Korean Navy on November 2 and interrogated.

Pyongyang approved the duo’s return by Seoul, according to TV news reports, which took place at 3:10 on Thursday afternoon.  Inter-Korean contact was made via the Inter-Korean Joint Liaison Office established last year in Kaesong, just north of the DMZ.

“As a result of a [domestic] joint investigation, the men in their 20s were found to have killed 16 fellow crew members and fled from a squid fishing boat operating on the East Sea,” a spokesperson told Yonhap news agency. Koreans call the Sea of Japan the East Sea.

Due to their “serious non-political crimes” the two men were a threat to South Korean safety and “could not be recognized as refugees under international law but as violent criminals,” the spokesperson added.

A bloody mutiny

According to the investigation, the two men claimed they had been part of a trio who had been abused by the captain of the squid boat. They decided to murder not only the captain, but also the rest of the crew, for fear of being reported. After the killing, they dumped the bodies overboard.

Upon returning to the port of Kimchaek in North Korea, one of the three was apprehended by North Korean police – prompting the other two to escape to sea, South Korean Unification Minister Kim Yeon-chul said in a briefing, according to Yonhap news agency.

The two were spotted by a South Korean reconnaissance plane on October 31, South Korean media reported, and were captured by a South Korean Navy ship on November 2.

South Korean ships routinely intercept vessels that stray across the Northern Limit Line, or NLL, the de facto maritime border between the two Koreas, though it is not yet known if the South Korean navy had been appraised of the murders.

Early media reports indicate that the murders were conducted with blunt instruments, raising the question of how three men could physically overpower 16. However, some North Korean fishing boats in the Sea of Japan do carry firearms, as seen in recent firefights between North Korean poachers and Russian security units.

Though it is common for North Korean fishermen who drift off course and into South Korean waters to be repatriated if they so request, the adjunct of a murder – let alone a mass murder – is highly unusual.

However, there were two gruesome cases in which North Korean commandos killed the crew members of North Korean mini-submarines that ran aground during clandestine operations in the 1990s in order to maintain mission security.

A rushed process?

Wannabe defectors who arrive in the South are extensively debriefed and screened. However, there have long been rumors that North Korean criminals – such as embezzlers and human traffickers – have made it through the process, Go Myong-hyun, a North Korea expert at the Asan Institute told Asia Times, but “murder is a different case,” he emphasized.

However, he questioned the speed and lack of transparency in Seoul’s investigation.

“It looks like everything was conducted in a hurry and entirely without disclosure, and [Seoul] did not announce anything until they had already returned the men,” Go added. “To me that is quite problematic.”

Questions related to the case were being asked in the National Assembly on Thursday afternoon.