Malaysian police investigating killing of Kim Jong Un's half-brother arrest second woman

He was apparently assassinated at Kuala Lumpur International Airport, where a woman carrying Vietnamese travel documents had earlier been arrested.

Kim Jong Nam died on Monday after suddenly falling ill at the airport.

According to a Malaysian government official, he told medical workers before he died that he had been attacked with a chemical spray.

Investigators are trying to shed light on a death that sparked speculation over whether North Korea sent a hit squad to kill a man known for his drinking, gambling and complicated family life.

Medical workers completed a post-mortem late on Wednesday, but it was not immediately clear if or when Malaysia would release the findings publicly.

North Korea had objected to the post-mortem, and asked for Kim Jong Nam's body to be returned.

Malaysia went ahead with the procedure anyway as the North did not submit a formal protest, said Abdul Samah Mat, a senior Malaysian police official.

The first suspected arrested was carrying travel documents bearing the name Doan Thi Huong.

She was identified using earlier surveillance video from the airport, police said.

Still photos of the video, confirmed as authentic by police, showed a woman in a skirt and long-sleeved white T-shirt with "LOL" emblazoned across the front.

Kim Jong Nam, who was 45 or 46, was estranged from his younger brother and had been living abroad for years.

He reportedly fell out of favour when he was caught trying to enter Japan on a false passport in 2001, saying he wanted to visit Tokyo Disneyland.

According to two senior Malaysian government officials, the elder Kim died en route to a hospital on Monday after suddenly falling ill at the airport's budget terminal.

Multiple South Korean media reports, citing unidentified sources, said two women believed to be North Korean agents killed him with some kind of poison before fleeing in a taxi.

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

South Korea's spy agency, the National Intelligence Service, said on Wednesday that North Korea had been trying for five years to kill Kim Jong Nam.

The NIS said Kim Jong Nam sent a letter to Kim Jong Un in April 2012, after an assassination attempt, begging for the lives of himself and his family.

The letter said: "I hope you cancel the order for the punishment of me and my family. We have nowhere to go, nowhere to hide, and we know that the only way to escape is committing suicide."

Although Kim Jong Nam had been originally tipped by some outsiders as a possible successor to his late dictator father, Kim Jong Il, others thought that was unlikely because he lived outside the country, including recently in Macau.

AP