The reports - which could not be immediately be verified - said Kim's half-brother, Kim Jong Nam, was attacked at Kuala Lumpur airport Monday by two women who fled the scene, according to accounts by South Korea's TV Chosun, a cable channel.
The document also showed that in December 2013, the month Jang was executed, the North Korean regime circulated a list of Jang and 15 other people convicted of treason among the country's foreign diplomatic missions and ordered them to remove the pictures or works of the listed people.
If an assassination is confirmed, it would be in keeping with the modus operandi of the North Korean regime. In 2016, however, Kim Jong-un's aunt, who has lived in the U.S. for almost two decades, told The Washington Post that the younger son had been designated the next leader when he was still a child.
A day before Kim Jong Un was officially proclaimed as their father's successor, Kim Jong Nam told Japan's Asahi TV that he opposed dynastic succession although he did not oppose his brother's rise to power because of unspecified "internal factors". North Korea does have a history of sending agents overseas to perform kidnappings, attacks, and assassinations, the BBC reports.
He was embarrassingly detained at a Tokyo airport, trying to enter Japan to visit Disneyland on a false Dominican Republic passport, accompanied by two women and a child.
Jong-nam, who studied in Russian Federation and Switzerland, was a computer enthusiast and fluent Japanese speaker.
The man reportedly said that the Chinese government was monitoring him, saying in 2012: "The Chinese government is protecting me, but it is also monitoring me too".
North Korea is known to target critics, mostly inside the secretive state.
Who is Kim Jong-nam?
Kim Jong Nam's mother was an actress who later became mistress to his father Kim Jong IL. It was reported that the agents had "poison needles" which did the job per South Korean media outlets, according to The Washington Post.
Kim told Yoji Gomi the country would collapse without reform, but reform would lead to the collapse of the Kim dynasty, while noting his brother would be little more than a puppet figure, used by the ruling elite.
Koh Yu-hwan, a professor at the Dongguk University in Seoul said that Jong-nam had previously been the subject of speculation that he could replace his younger half-brother.
"I hope my younger brother will do his best for the sake of North Koreans' prosperous lives".
"It seems probable that the motivation for the murder was a continuing sense of paranoia on the part of Kim Jong Un, which may be a well-placed paranoia", Tokola wrote in a commentary today.