Malaysia has asked Interpol to put out an alert for four missing North Korean suspects wanted in connection with the death of Kim Jong-nam, the police said on Thursday.
Malaysian Inspector-General Tan Sri Khalid Abu Bakar said the police had also formally requested an interview with the North Korean embassy's Second Secretary Hyon Kwang-song, who is wanted for questioning in the case, CNN reported.
Kim Jong-nam, the half brother of North Korean leader Kim Jong-un, died last week after a suspected poisoning while on his way to catch a flight to the Chinese territory of Macau from Kuala Lumpur Airport.
North Korea furiously denied any involvement in Kim's death, according to a report in the country's state media KCNA.
According to KCNA report, a spokesman for the Korean Jurists Committee said the responsibility for Kim's death lay with Malaysia, as he had died on their territory, and criticised the investigation.
"If you look at Malaysian police's investigation from crime investigation perspective and legal perspective, everything is full of weak points and contradictions," KCNA quoted the spokesman as saying.
Interpol notices were issued to the police in 190 different countries to help track fugitives and share information about wanted criminals, CNN report said.
The Malaysian police previously said the four suspects who are the subject of the alert were believed to be back in Pyongyang.
In addition to the four suspects, the Malaysian police named the North Korean embassy's second secretary and a state airline official, who they said were wanted for questioning over the killing of Kim Jong-nam. Both are believed to still be in Malaysia.
Bakar said the North Korean embassy wouldn't be searched as they had diplomatic immunity.