Malaysian police say they have arrested a third person in connection with the apparent poisoning death of Kim Jong-nam, the half-brother of North Korean dictator Kim Jong-un.

A police official said officers detained a Malaysian man on Wednesday evening. He reportedly provided information that led to earlier arrests of two women.

The man is believed to be the boyfriend of the second suspect, who was holding an Indonesian passport that identified her as 25-year-old Siti Aishah, a Malaysian police statement said.

Before that Malaysian police had detained another woman holding Vietnamese travel papers.

The documents she carried were in the name of Doan Thi Huong, and showed a birth date of May 1998 and birthplace of Nam Dinh, Vietnam, police said.

The woman, detained at Kuala Lumpur airport, was identified from CCTV footage at the airport and was alone when she was apprehended, police said in a statement.

CCTV footage shows one of the suspects in Kim Jong-nam’s murder.

Media had earlier published a grainy CCTV-captured image of a young woman wearing a white shirt with the letters “LOL” on the front.

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

Also Thursday, medical workers completed an autopsy on Kim Jong-nam, who was suspected of being poisoned week by two female assassins as he waited for a flight in Malaysia.

North Korean government officials in Malaysia reportedly objected to the autopsy being performed and requested the body be released to them right away.

It was not immediately clear if or when Malaysia would release the Autopsy findings publicly.

South Korean politicians earlier cited their spy agency as saying it suspected two female North Korean agents had murdered Kim Jong-nam, and US government sources also told Reuters they believed North Korean assassins were responsible.

The portly and gregarious Kim Jong-nam, the eldest son of late North Korean leader Kim Jong-il, was assaulted on Monday morning in the departure hall of Kuala Lumpur International Airport and died on the way to hospital, Malaysian police said.

South Korean intelligence believes Kim Jong-nam was poisoned, the MPs in South Korea’s capital, Seoul, said.

The spy agency told them that the young and unpredictable North Korean leader had issued a “standing order” for his 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.

Kim Jong–nam pictured in 2010 in Macau. Photo: Getty

According to South Korea’s spy agency, Kim Jong-nam had been living, under Beijing’s protection, with his second wife in the Chinese territory of Macau, the MPs said. One of them said Kim Jong Nam also had a wife and son in Beijing. 

Malaysian police said Kim held a passport under the name Kim Chol, with a birth date that made him 46.

Kim Jong-nam was known to spend a significant amount of time outside North Korea, travelling in Macau and Hong Kong, as well as mainland China, and had been caught in the past using forged travel documents.

There was no mention of Kim Jong-nam’s death in North Korean media.

North Korea is celebrating the 75th birth anniversary of his father, Kim Jong-il, one of the biggest festivities held in the Asian country, oblivious to the regime’s latest missile test and the assassination of the current leader’s half-brother.

– With AAP