TOKYO (KOREA HERALD/THE STAR/ASIA NEWS NETWORK) - The two women who allegedly killed Mr Kim Jong Nam, half-brother of North Korean leader Kim Jong Un, in Malaysia on Monday (Feb 13) may already be dead, Japan's Kyodo News reported.

"There have been reports that (the two suspects) may already be dead," the news outlet said, citing a ranking official of the Japanese government.

The official, however, did not specify the cause of their assumed death, be it homicide or suicide.

North Korean special agents had in the past attempted suicide after their missions. An example was Kim Hyun Hee, the convicted bomber of a South Korean airplane in 1987 under the direction of the North Korean regime. After carrying out the act which led to the deaths of 115 passengers, Kim tried to commit suicide but failed.

Mr Kim Jong Nam, 46, died on Monday after being attacked by two unidentified women at the Kuala Lumpur International Airport. They were presumed to be North Korean undercover agents on a mission to eliminate the estranged half-brother of President Kim.

Mr Kim Jong Nam was attacked while he was waiting for his flight to Macau.

"He told the receptionist at the departure hall that someone had grabbed his face from behind and splashed some liquid on him," Selangor state's criminal investigation chief Fadzil Ahmat said.

"He asked for help and was immediately sent to the airport's clinic. At this point, he was experiencing headache and was on the verge of passing out," he said.

"At the clinic, the victim experienced a mild seizure. He was put into an ambulance and was being taken to the Putrajaya Hospital when he was pronounced dead."