Kim Jong Nam, the half-brother of North Korean leader Kim Jong Un who was killed in Malaysia in 2017, had been an informant for the US Central Intelligence Agency, the Wall Street Journal reported on Monday.

WSJ cited an unnamed “person knowledgeable about the matter” for the report, and said many details of Kim Jong Nam’s relationship with the CIA remained unclear.

Reuters could not independently confirm the story. The CIA declined to comment.

WSJ quoted the person as saying “there was a nexus” between the CIA and Kim Jong Nam.

“Several former US officials said the half-brother, who had lived outside of North Korea for many years and had no known power base in Pyongyang, was unlikely to be able to provide details of the secretive country’s inner workings,” WSJ said.

The former officials also said Kim Jong Nam had been almost certainly in contact with security services of other countries, particularly China’s, WSJ said.

South Korean and US officials have said the North Korean authorities had ordered the assassination of Kim Jong Nam, who had been critical of his family’s dynastic rule. Pyongyang has denied the allegation.

Two women were charged with poisoning Kim Jong Nam by smearing his face with liquid VX, a banned chemical weapon, at Kuala Lumpur airport in February 2017. Malaysia released Doan Thi Huong, who is Vietnamese, in May, and Indonesian Siti Aisyah in March.

According to WSJ, the person said Kim Jong Nam had travelled to Malaysia in February 2017 to meet his CIA contact, although that may not have been the sole purpose of the trip.

US President Donald Trump and Kim Jong Un have met twice, in Hanoi in February and Singapore last June, seeming to build personal goodwill, but failing to agree on a deal to lift US sanctions in exchange for North Korea abandoning its nuclear and missile programmes.

- Reuters