DNA from a child, sibling — or even half-sibling — would be enough to provide a “kinship match” and confirm the identity, a Malaysian forensic investigator told AFP.
Police were meanwhile questioning two women — one traveling on a Vietnamese passport and the other on an Indonesian document — as well as a Malaysian man.
The drama erupted on Monday morning as Jong-Nam, the estranged elder brother of Kim Jong-Un, readied to board a plane to Macau.
Malaysian police say the chubby 45-year-old was jumped by two women who squirted some kind of liquid in his face.
Jong-Nam told staff he was suffering from a headache and was taken to the airport clinic grimacing in pain, according to Malaysian media citing CCTV footage from the airport.
One of the women walked to a taxi rank immediately after the attack, according to the same footage.
He was rushed to hospital suffering from a seizure but was dead before he arrived.
South Korea has pointed the finger of blame at the North, citing a “standing order” from Jong-Un to kill his sibling and a failed assassination bid in 2012 after he criticized the regime.
A Japanese journalist who knew and wrote a book on Jong-Nam on Friday said he was a courageous man who sought to reform his country.
“Even if it put him in danger, he wanted to tell his opinions to Pyongyang through me or other media,” Yoji Gomi said in Tokyo.
Pyongyang has made no comment on the killing, and there has been no mention of it in North Korean media.
AFP correspondents in Pyongyang say celebrations to mark the birthday of Kim Jong-Il, the late father of both men, have gone ahead without reference to the death.
Malaysian police on Wednesday arrested a 28-year-old woman carrying a Vietnamese passport which identified her as Doan Thi Huong.
Local media said she was the woman seen in CCTV images from the airport wearing a white top with the letters “LOL” emblazoned on the front.
Officers later arrested Muhammad Farid Bin Jalaluddin, a 26-year-old Malaysian man. He led them to his girlfriend, a 25-year-old Indonesian national named Siti Aishah.
Aishah’s family in Jakarta expressed their shock over her arrest, with her former father-in-law saying there was “no way such a nice person would do that.”
“I could not believe it because she was a good person,” said Tija Liang Kiong, 56.
Indonesian Vice President Jusuf Kalla said Aishah appeared to be the “victim of a scam or a fraud” who thought she was taking part in a reality show involving hidden cameras.
Indonesian Embassy officials said they were providing Aishah with legal assistance.
Selangor state police chief Abdul Samah earlier told AFP he was looking for several more suspects, but declined to say how many were being sought.