Did Kim Jong-un kill his uncle and brother over 'coup plot involving China'?
Kim Jong-un, the North Korean dictator, reportedly ordered the execution of his uncle and mentor in December 2013 after learning that Jang Song-thaek had proposed to China that it support a coup to replace Mr Kim with his half-brother, Kim Jong-nam.
Mr Jang met in Beijing with Hu Jintao, the then-Chinese president, in August 2012, according to reports in Japan's Nikkei Asian Review. Mr Jang had cultivated close business and political ties with China and was trusted by Beijing.
Sources told the newspaper that Mr Jang proposed a plot to overthrow Mr Kim, with Beijing's assistance, and to replace him with his oldest half-brother.
Mr Hu was not in a position to give an immediate answer to the suggestion, however, as he was facing an internal crisis of his own. Mr Hu's closest adviser, Ling Jihua, was facing disgrace after his fast-living son was killed in a speeding Ferrari when it crashed in Beijing.
The alleged plot was discovered by Zhou Yongkang, a former member of China's Politburo Standing Committee and a close aide to another former president, Jiang Zemin. As head of the police and Ministry of State Security, Mr Zhou had built up connections with North Korea, including with Kim Jong-un.
Internal political rivalries convinced Mr Zhou to inform Mr Kim - who had only taken over control of North Korea after the death of his father in December 2011 - of the plan to stage a coup and replace him.
After hearing of the plot, "the North Korean leader flew into a rage" and, in December 2013, ordered the arrest and execution of Mr Jang.
The statement released after Mr Jang's arrest hints at the reasons for his nephew's ruthlessness, describing him as "human scum, who was worse than a dog" and claiming he "perpetrated thrice-cursed acts of treachery in betrayal of such profound trust and warmest paternal love shown by the party and the leader".
It added that he "had desperately worked for years to destabilise and bring down the DPRK and grab the supreme power of the party and state by employing all the most cunning and sinister means and methods".
It is not clear whether Kim Jong-nam had been involved in the plotting of the coup, although his assassination in Kuala Lumpur airport in February with VX gas would suggest that Kim Jong-un was taking no chances that he might one day usurp him.
Further supporting the theory is the apparent schism that has developed between Pyongyang and Beijing, a relationship that Mao Zedong once famously described as being as close as "lips and teeth".
Kim Jong-un | A history of executions - family, allies and rivals
"Jang was a North Korean who was doing things differently, appreciated the advances that were clear in the way China had modernised its economy and probably wanted the same for North Korea", said Bradley Martin, author of "Under the Loving Care of the Fatherly Leader: North Korea and the Kim Dynasty".
That alone might have been sufficient for him to be accused of treason, Martin said, although his fate would have been sealed as soon as Mr Kim heard of his coup plot.
"This also offers an explanation of why Kim went after his half-brother earlier this year", he said. "And also why, even more than five years after he took power, he has still not even visited China".
