Japan's Kyodo News said that the woman apprehended carried a South Korean passport.

Kim Jong-nam -- the eldest son of late former leader Kim Jong-il -- was killed at an airport in Malaysia on Monday after allegedly being attacked with poison by two women, according to South Korea's spy agency.

The first suspect, who held Vietnamese travel documents, was caught at the airport and Malaysian police suspect that a total of four men and two women were involved, according to foreign news reports.

South Korea's intelligence service said that the murder of Kim Jong-nam has been a "standing order" issued by Kim Jong-un since he inherited power in late 2011 following the sudden death of his father.

Kim Jong-nam, 46, was at the airport to take a flight to Macau and after being attacked by two "Asian" women, he died en route to a hospital.

The South Korean government confirmed Kim’s death, but stopped short of saying that North Korea was behind it, adding that it is awaiting the results of Malaysian police's probe.

"If Kim Jong-nam's murder was carried out by North Korea, the North's leader would have been aware of that," said an official at Seoul's unification ministry.

Kim Jong-nam was once viewed as the heir apparent, but he had been living in foreign countries for years after apparently falling out of favor with his father for attempting to enter Japan with a fake passport in 2001.

The latest case marked the most high-profile death under the Kim Jong-un regime since the execution of Jang Song-thaek in December 2013, the once-powerful uncle of the incumbent leader. (Yonhap)