Jong Kyong-thaek, a member of the central military committee of the Workers’ Party of Korea, was promoted to the high-ranking position this week, according to the Asahi Shimbun, a Japanese newspaper.
Kim Won-hong, the top officer in North Korea’s military, was reportedly removed from his post earlier this year, prompting the country’s leader to appoint Jong.
He was reportedly sent to a collective farm in Pyongyang where he was forced to work as a labourer.
The move is seen as part of Kim Jong-un’s plan to block his aides from building up too much power and authority within the totalitarian regime.
Alongside Kim Won-hong, it is believed that Hwang Pyong-so, the chief of the General Political Bureau of the Korean People’s Army, was removed from his post as a punishment for “impure acts”.
Choe Ryong-hae, the vice chairman of the party’s central committee, has reportedly led the purge.
In October the Institute for National Security Strategy, which is affiliated with South Korea’s National Intelligence Service (NIS), predicted that the North’s supreme leader was poised to appoint a new military chief.
It was then confirmed by the NIS that the North is conducting an “inspection” of the army’s General Political Bureau.
The news comes a week after North Korea suffered acute embarrassment as video footage emerged of a border guard fleeing across the joint security area (JSA) with the South.
The defector, identified only by his surname Oh, sped in a jeep towards the South before losing control and crashing into a ditch.
He sprinted the final few metres as North Korea guards opened fire, firing more than 40 rounds at him.
He was struck by at least five bullets but clung to life as he kept crawling towards South Korea.
Now those border guards are believed to be taking the full force of Kim Jong-un’s fury for the incident – with all believed to have lost their positions.
Yonhap News, a Seoul-based news agency, believes all border guards have been replaced at the border in a huge security overhaul.
And they said an intelligence source had told them the guards were also in danger of cruel punishment at the hands of Kim’s security agents.
The unnamed source told the agency: “Signs were detected that North Korea has replaced all border security officials following the defection.
“Given this situation, commanders of the responsible military unit and senior officers might have undergone punishment.”
The source also claimed North Korea is now tightening its screening of those entering and leaving the demilitarised zone as well as other aspects of security in the joint security area.