The older brother of North Korean leader Kim Jong Un has been assassinated at Kuala Lumpur's airport, according to reports.

Multiple South Korean media outlets, citing unnamed sources, said Kim Jong Nam died after being targeted in the Malaysian capital by two women using poison needles.

The district police chief, Abdul Aziz Ali, could not confirm the reports. He said only that a North Korean man was waiting for a flight to Macau on Monday when he fell ill and died en route to hospital.

Kim Jong Nam reportedly fell out of favour in North Korea after being caught trying to enter Japan on a false passport in 2001, saying he wanted to visit Tokyo Disneyland.

TV Chosun said the women are believed to be North Korean agents and are being sought by Malaysian police after fleeing in a taxi.

Kim Jong Nam is believed to be in his mid-40s and has been living in recent years in Macau.

A member of the staff at the emergency ward of Putrajaya Hospital said the deceased North Korean was born in 1970 and was known only as Kim.