Kuala Lumpur : The mysterious killing of Kim Jong’s half brother is unfolding new twists every day. As the killing is probed deeper and deeper new updates are enough to corner a few North Korean officials.

 Investigators have put five North Koreans in the frame for last week´s brazen killing of Kim Jong-Nam at Kuala Lumpur International Airport and have said they are seeking three more for questioning.

They include the embassy´s second secretary, Hyon Kwang Song, as well as a North Korean airline employee called Kim Uk Il, Khalid Abu Bakar told reporters.

"We have written to the ambassador to allow us to interview both of them. We hope that the Korean embassy will cooperate with us and allow us to interview them quickly. If not, we will compel them to come to us," he said.

Jong-Nam died on February 13 after being attacked as he waited for a plane to Macau.

Leaked CCTV footage from the airport shows the chubby 45-year-old being approached by two women, one of whom grabs him from behind and appears to shove a cloth in his face.

Moments later Jong Nam is seen seeking help from airport staff, who direct him to a clinic, where he apparently slumped in a chair.

Malaysian police say he suffered a seizure and died before he reached hospital, seemingly from the effects of a toxin.

Seoul has said from the start that Pyongyang was behind the murder, citing a "standing order" from Jong-Un to kill his elder sibling, and a failed assassination bid in 2012.