The estranged half-brother of North Korean leader Kim Jong-un appears to have been assassinated in a James Bond-like attack involving poisoned darts or a spray toxin.

A South Korean government source says Kim Jong-nam, who has spoken publicly against his family’s dynastic control, was murdered in Malaysia.

Police official Fadzil Ahmat said that the cause of Kim’s death had not been determined yet, but that a post mortem would be carried out on the body.

Police are checking surveillance tapes for clues about who may have been responsible for the assassination, with an autopsy to be performed on Wednesday.

According to Fadzil, Kim had been planning to travel to Macau on Monday when he fell ill at the Kuala Lumpur International Airport.

“The deceased … felt like someone grabbed or held his face from behind,” Fadzil said. “He felt dizzy, so he asked for help at the … counter of KLIA.”

Kim was taken to an airport clinic where he still felt unwell, and it was decided to take him to hospital.

He died in the ambulance on the way to Putrajaya Hospital, Fadzil added.

South Korea’s TV Chosun, a cable television network, reported that Kim had been poisoned with a needle by two women believed to be North Korean operatives who fled in a taxi and were at large, citing multiple South Korean government sources.

A US government source has also told Reuters that the US believes North Korean agents were behind the murder.

American authorities have not yet determined exactly how he was killed but it could not be ruled out that assassins used some kind of “poison pen” device, according to two sources.

Bond assassination, Austin Powers life

Kim Jong–nam was once heir–apparent to the world’s only communist dynasty, but he suffered a dramatic fall from grace and was forced into exile until the death of his father in 2011 — whereupon he went into hiding to evade a half-brother who feared he posed a threat to his own rule.

North Korean Leader Kim Jong Il, bottom left, poses with his first-born son Kim Jong Nam, bottom right, in a family photo from 1981. Photo: Getty

He had no political ambitions and preferred to travel, seemingly on forged passports from Portugal or the Dominican Republic. He used a Chinese alias, Pang Xiong, which means “fat bear” in Mandarin.

He fell out of favour with the regime after being caught trying to enter Japan on a false passport in 2001, saying he wanted to visit Tokyo Disneyland.

Kim Jong-nam reportedly left Macau in late 2012 after becoming concerned for his safety; a North Korean agent arrested in South Korea admitted during questioning that he had been tasked with assassinating Kim in July 2010 and there were reports of a failed attempt on his life in the city shortly after the death of his father.

Kim Jong-nam later spent time in Singapore before being spotted in Malaysia in January 2014.

In his book Under the Loving Care of the Fatherly Leader, Bradley Martin stated that Kim Jong-nam had been a visitor to Japan on numerous previous occasions and was a regular client in some of the bathhouses in the Yoshiwara red-light district of Tokyo.

In the book, Kim Jong–nam said he expected the regime of Kim Jong–un to collapse because he was too young and inexperienced.

For the next several days, North Korea will be marking the birthday of its late leader Kim Jong-il.

Since taking power in late 2011, Kim Jong-un has executed or purged a slew of high-level government officials in what the South Korean government has described as a “reign of terror”.

The most spectacular was the 2013 execution by anti-aircraft fire of his uncle, Jang Song-thaek, once considered the country’s second-most-powerful man, for what the North alleged was treason.

– with agencies