Malaysian police have detained the boyfriend of a second woman arrested over the murder of Kim Jong-nam, the half brother of North Korean leader Kim Jong-un.

Key points: Two women identified on CCTV arrested over murder of Kim Jong-nam at Kuala Lumpur airport

Two women identified on CCTV arrested over murder of Kim Jong-nam at Kuala Lumpur airport A suspect arrested on Wednesday carried Vietnamese travel documents, while the second suspect held an Indonesian passport

A suspect arrested on Wednesday carried Vietnamese travel documents, while the second suspect held an Indonesian passport Police say they are looking for more foreign suspects over the killing

"He was detained to facilitate investigations as he is the boyfriend of the second suspect," Selangor state police chief Abu Samah Mat said.

Police said the woman was identified through CCTV footage and was carrying an Indonesian passport when she was arrested at 2:00am local time (4:00am AEDT) on Thursday.

Indonesia's Foreign Ministry said it had confirmed the woman was an Indonesian citizen. Her travel documents said her name was Siti Aishah and she was born on February 11, 1992 in Serang, Indonesia.



On Wednesday, police detained a different woman holding Vietnam travel papers and said they were looking for a "few" other foreign suspects in connection with the murder.

Kim Jong-nam, 46, was murdered at an airport in Kuala Lumpur, telling medical workers before he died that he was attacked with a chemical spray, a Malaysian official said.

He was targeted in the shopping concourse at Kuala Lumpur International Airport (KLIA) and had not gone through immigration yet for his flight to Macau, said a senior government official, who spoke on condition of anonymity.

A Malaysian government source confirmed the first suspect arrested was the same woman whose image was captured by CCTV footage and published by media.

The grainy picture showed her wearing a white shirt with the letters "LOL" on the front.

Police said she was alone when she was picked up, and held travel documents in the name of Doan Thi Huong showing a birth date of May 1988 and birthplace of Nam Dinh, Vietnam

She was due to face court in Kuala Lumpur on Thursday.

Hunt on for other suspects in killing

"Police are looking for a few others, all foreigners," Deputy Inspector-General Noor Rashid Ibrahim said, declining to give their nationalities or gender.

There has been no mention of Kim Jong-nam's death in North Korean state media and at midnight, North Korean leader Kim Jong-un visited the Kumsusan Palace of the Sun to mark the birthday of their father, the late leader Kim Jong-il, who died in 2011.

A CCTV still showed a woman, believed to be connected to Kim's death, wearing a 'LOL' shirt. ( AP/Star TV )

South Korea's intelligence agency told lawmakers in Seoul the young and unpredictable North Korean leader had issued a "standing order" for his elder half-brother's assassination, and that there had been a failed attempt in 2012.

"The cause of death is strongly suspected to be a poisoning attack," said South Korean lawmaker Kim Byung-kee, who was briefed by the spy agency.

Politicians in South Korea earlier cited their spy agency as saying it suspected two female North Korean agents had murdered Kim Jong-nam. US Government sources also said they believed North Korean assassins were responsible.

Malaysian authorities rebuffed North Korean officials' efforts to stop an autopsy being carried out on Kim Jong-nam, three Malaysian government sources said.

Speaking to reporters, Malaysia's Deputy Prime Minister said he believed the police had received a request from North Korean officials for the body, and it could be eventually released to the North Korean embassy.

"After all the police and medical procedures are completed, we may release the body to the next of kin through the embassy," Ahmad Zahid Hamidi said.

According to South Korea's spy agency, Kim Jong-nam had been living with his second wife, under Beijing's protection, in the Chinese territory of Macau.

ABC/Reuters