The half-brother of North Korean leader Kim Jong-un, Kim Jong-nam, has been killed in an attack in the Malaysian capital, Kuala Lumpur.
Malaysian police say he was waiting at the airport for a flight to Macau on Monday when a woman covered his face with a cloth which burnt his eyes.
He was using a passport in a different name at the time.
The late Kim Jong-il’s eldest son is thought to have fled North Korea after being passed over for the leadership.
Kim Jong-nam was attacked at about 09:00 (01:00 GMT) on Monday while waiting at the budget terminal of Kuala Lumpur International Airport for a 10:00 flight to Macau, Malaysia’s Star newspaper reports, quoting police.
How the attack actually happened is still unclear. Malaysian police official Fadzil Ahmat told The Star that Mr Kim had alerted a receptionist, saying “someone had grabbed him from behind and splashed a liquid on his face”.
But quoted by Malaysian news agency Bernama, the same official said a woman had come at him from behind and “covered his face with a cloth laced with a liquid”. Earlier reports spoke of a “spray” being used or a needle.
His eyes “suffered burns as a result of the liquid”, Fadzil Ahmat told Bernama, and he died on the way to hospital in nearby Putrajaya.
“So far there are no suspects, but we have started investigations and are looking at a few possibilities to get leads,” Fadzil Ahmat told Reuters news agency separately.
Bypassed in favour of his youngest half-brother for succession when their father died in 2011, Kim Jong-nam kept a low profile, spending most of his time overseas in Macau, mainland China and Singapore.
He is said to have enjoyed the slot machines in Macau, a Chinese territory famous for gambling.
Mr Kim was reportedly targeted for assassination in the past.
A North Korean spy jailed by South Korea in 2012 was reported to have admitted trying to organise a hit-and-run accident targeting him.
The secretive state has a long history of sending agents overseas to carry out assassinations, attacks and kidnappings.