Kim Jong-nam and Kim Jong-un are both sons of former leader Kim Jong Il, who died in late 2011, but they had different mothers.
The half-brother of North Korean leader Kim Jon-un has been assassinated in Malaysia. Kim Jong-nam was killed on Monday, according to reports from South Korean media.
He was allegedly killed with poisoned needles by two women at Kuala Lumpur airport and died en route to hospital.
Malaysian police have confirmed that the dead man was indeed Kim Jong-nam but have not yet determined the cause of death.
TRT World's Adam Reed is following the story from Seoul.
Nithyanantham Sivananthan, a council member of the International Criminal Bar, also had this to say from Kuala Lumpur.
Who was Kim Jong-nam?
Kim Jong-nam, was the son of South Korean born actress Sung Hae-rim, who was believed to have been a mistress of Kim Jong-il. His mother died in exile in Russia in 2002.
The older half brother of the North Korean leader, Kim Jong-nam was known for his gambling and playboy lifestyle. He also spent a significant amount of his time outside the country, and had spoken out publicly against his family's dynastic control of the isolated state.
He was disowned after being arrested in 2001 while travelling on a forged passport. He was said to have been trying to visit Tokyo Disneyland.
During interviews with Japanese media he reportedly said he was against a third generation succession in North Korea, and hoped his younger brother would do what was best for the country.