Or agents of evil?
a diplomat and a scientist, have been implicated in the plot.
But Pyongyang have even denied the victim’s identity.
It has been suggested Kim Jong-un’s motive was jealousy, as well as a fear that his brother could emerge as a rival leader.
Kim Jong-nam – the product of their father Kim Jong-il’s affair with a married actress – had been living in exile in the Chinese territory of Macau.
He was sent there after being caught out trying to go to Disneyland on a false passport in an incident which angered and embarrassed his father.
He claimed he had no desire to become leader of North Korea but offended his brother by saying he was opposed to the third-generation succession which had given him power.
North Korea expert Michael Madden said: “Jong-nam was viewed by some elderly North Korean elites as a kind of grandson figure.
“He still had a power base and there was always a remote possibility he would take power.”
South Korea’s intelligence agency claim Jong-nam pleaded with his brother five years ago not to harm him or his family.
And, soon after his death, a friend claimed: “He knew his life was at risk … and he was aware his brother was after him.”
Former CIA analyst Sue Mi Terry said: “However improbable, there were always rumours Jong-nam could replace Kim Jong-un at the behest of China or the US.”
So, as the despot was already planning his nuclear build-up, did he decide to do away with his rival and send a message of power to the US and the world?
Another North Korean expert said: “Kim is testing nukes and missiles like crazy and feels confident enough to send his goons around the world to assassinate rivals.
“It’s a sign of supreme confidence that he can literally get away with murder.”
The strangest theory of all comes from Brad Glosserman, executive director of the Center for Strategic and International Studies in the US.
He believes China – a key ally of North Korea – removed Jong-nam’s secret service protection and allowed the assassination to happen as a symbol of support to Pyongyang.
Following the murder, an apparently angry China stopped coal imports from North Korea.
But Glosserman believes this was just for show and that China had already imported their quota.
He said: “Because, in theory, he was under their protection, the Chinese may have let that assassination occur.
“It would have been a way of signalling to Pyonyang that even if they are moving forward with the sanctions on the coal exports and tightening the screws, this is proof they are not really out there to overthrow the regime.”
Meanwhile, scientific evidence presented in court suggests Jong-nam may have been poisoned by means other than the contaminated face cloth.
Traces of VX were found not just on his face and eyes but also in his blood and urine and on his clothing.
North Korea deny any involvement in the killing and insists the dead man is not Kim Jong Nam but Kim Choi – the name on his false passport.