During a 30-minute clip showing the hermit kingdom’s arms and munitions industry conference on the 12 December, users are given a previously unseen glimpse of what appears to be the late Kim Jong-il inspecting a bomb.

The deadly weapon looks remarkably similar to the claimed hydrogen bomb that Kim Jong-un posed with earlier this year.

The picture can be seen during a clip of a wall displaying the rogue nation’s military achievements.

The footage is not of a high enough quality to determine specific details about the weapon - the photo has never been seen before by the west.

The shocking slip up was first revealed by a user on Twitter that posted “the munition industry meeting is also a missile exhibition”.

He added: “Is that an A-bomb or something?”

North Korea’s puppet news agency, KCNA, stated the conference was designed to review “the achievements and gains in the work to implement the party's policy on the munitions industry" and give “full play to the invincible might of socialist Korea”.

Shea Cotton of the James Martin Centre for Nonproliferation Studies stated that based on the size of the device being inspected by the late ruler of the hermit kingdom, it could be an atomic bomb.

He said: "Kim Jong-il carried out the regime's first two tests so they definitely had [atomic weapons] during his time and they probably were about that size.

"I don't believe this was accidentally released as part of some slip-up, but neither do I think this was a purposeful act. I think in many ways, the regime doesn't care if we [the US] know they have these weapons.”

The recent conference in the isolationist kingdom are usually known for being low-key, however, the mood was decidedly celebratory following a series of successful provocative missile tests.

Presented by Ri Chun-hee, the news reader that has become a staple of North Korean bulletins, she said the country’s military first policies had succeeded despite a wealth of sanctions being imposed on Kim Jong-un.

In an attempt to brainwash its people, the word “victory” is used with regularity as the country continues to push its threatening military programme further than ever.

The televised propaganda was dampened by KCNA’s recent blunder that revealed the rogue state has experienced droughts this year that have affected crops.

Kim Jong-un remarked at the end of the conference that North Korea needs to “"bolster up the nuclear force in quality and quantity, manufacture more [of the] latest weapons and equipment of Korean style”.

Kim Jong-il became the leader of North Korea in 1994 after the death of his father, Kim Il-sung.

Jong-il’s time in power is marked with issues of famine in the isolationist kingdom and poor human rights.

The ruler died in 2011 and was succeeded by current despot Kim Jong-un.