Kim Jong-un is using barbaric methods to 'purge' his officials and cling onto power, according to a damning South Korean investigation.

The dictator has had 421 officials executed and exiled since seizing power in 2011, with victims being fed naked to hunting dogs, blown up with anti-aircraft guns, burned alive with flamethrowers and hanged, the report claims.

In some cases, entire families of officials have been executed while others were imprisoned in concentration camps and 'erased from society'.

Kim Jong-un (pictured in Vietnam ahead of his summit with Donald Trump) has purged 421 officials since seizing power in 2011, including his own family members, according to a damning South Korean report

The dictator (waving on arrival at Dong Dang Station, flanked by his security) has had victims fed naked to animals, blown up with anti-aircraft guns, hanged and burned alive with flamethrowers, the report claims

Kim is also said to have ordered the execution of his own family members, including his uncle Jang Song Thaek, who was executed in 2013, and his half-brother Jong-nam, who was assassinated at a Malaysian airport in 2017.

When the North Korean leader had his uncle Jang killed, 'more than 15 people were killed and 400 others were purged,' according to the collection of accounts from high-ranking defectors.

Titled 'Executions and Purges of North Korean Elites: An Investigation into Genocide Based on High-Ranking Officials' Testimonies', the report was researched by the Seoul-based North Korean Strategy Centre (NKSC).

It combined the accounts of 14 North Korean elite group defectors, six North Korean officials in China and five other defectors who witnessed executions.

The investigation found that Kim ordered the execution of his uncle because Jang 'sold the country's resources to foreign countries at a low price.'

It also claims officials faced death or imprisonment for minor infractions such as slouching at an event attended by the supreme leader.

The report lists the full names of more than 50 purged victims, while confirming that hundreds more were executed but never named.

Moon, a former student at Pyongyang Commercial College, said in the report he'd witnessed a 12-man public execution by soldiers using four anti-aircraft guns.

He said that, one-by-one, four guns blew up the victims, according to Radio Free Asia (RFA), before armored vehicles were used to crush their remains.

Moon said he suffered from PTSD following the killings.

The report was analysed at a Human Rights panel discussion in Washington last Friday.

Jared Genser, a member of Human Rights in North Korea's (HRNK) International Advisory Council, explained that these methods were to strike fear into the hearts of the entire population, from the average citizen to high ranking officials.

The report claims Kim had his uncle Jang Song Thaek - the vice chairman of the National Defense Commission - in 2013 because he 'sold the country's resources to foreign countries at a low price'

'They need to instill fear into people working for the authoritarian leader, and they need to keep people at bay by making them very fearful that anything they say or do could result in torture, extrajudicial killing, arbitrary detention and so forth,' Genser said, RFA reports.

He issued a plea to US President Donald Trump to raise human rights with Kim as they discuss nuclear disarmament at their summit in Hanoi today.

'Read this report that has hard evidence of the facts, and they're corroborated. Know your counterpart, who he is. The single most important issue when dealing with him is not denuclearization. It is the human rights issue,' said Kang.

Kim crossed into Vietnam with fanfare and a red carpet on Tuesday – as an attendant scurried looking like his life depended on it to catch up to be by the absolute leader’s side.

Kim's half-brother Jong-nam, who was assassinated in 2017 by two women who attacked him with a nerve agent at Kuala Lumpur International Airport in Malaysia

The North Korean dictator later drove to Hanoi after a 2,800 mile train journey, accompanied by dozens of security guards who sprinted to surround him as he entered the Hotel where he will stay until his summit with President Trump.

Included in his lengthy motorcade that snaked its way through the Vietnamese capital was an armored vehicle complete with a mounted gun turret on top.

It later parked itself around the corner from Kim's hotel, while locals on scooters made their way through the city's packed streets.

As he reached his final destination, Kim's team of protective agents jumped out of a line of black SUVs to enter Kim’s hotel. They could be seen riding with vehicle doors open, then rushing to the heavily-guarded leader.