Malaysian authorities wrongly identified the slain half-brother of North Korea’s leader as a South Korean national and first alerted Seoul’s embassy in Kuala Lumpur soon after his death, sources familiar with the incident say.

The police error did have a silver lining: it enabled Seoul to quickly inform Kuala Lumpur the dead man was probably Kim Jong-nam, half-brother to North Korean leader Kim Jong-un.

Kim was murdered on February 13, when Malaysian police say two women smeared super toxic VX nerve agent on his face at Kuala Lumpur International Airport.

After examining the victim’s passport, Malaysian authorities confused the Democratic People’s Republic of Korea, the formal name of North Korea, with the Republic of Korea, the official name of its estranged southern neighbour, the sources told Reuters.

Malaysian authorities contacted the South Korean embassy, sending along copies of documents found on Kim’s body.

After the mix-up was realised, North Korea’s diplomatic mission in Kuala Lumpur was informed on the day of the murder, the sources said.

Malaysian police did not respond to requests for comment.

The confusion over Kim’s nationality also explains why it was the South Korean media that initially broke the news.

Within 24 hours of his death, South Korea’s National Intelligence Service had briefed lawmakers in Seoul that Kim Jong-nam was believed dead.

It then was leaked to the South Korean media.

Hours after the news emerged in South Korea, Malaysian police confirmed a North Korean man had died at the airport, without disclosing his identity.

South Korean and US intelligence sources say North Korea masterminded the attack, which Pyongyang denies.

The North Koreans might never have acknowledged the slain man to be Kim Jong-un’s half-brother if Malaysian police had sent his passport to their mission in Seoul instead of the South Korean embassy.