CCTV footage of the moment Kim Jong-un’s half-brother was allegedly attacked at Kuala Lumpur International Airport has been leaked.

The footage, released by Japanese broadcaster Fuji TV, shows the suspected assassination of Kim Jong-nam, the 46-year-old half-brother of North Korea’s leader who had been living under the protection of Beijing in the Chinese territory of Macau.

The CCTV footage appears to show a woman attack a man believed to be Kim Jong-nam in the busy concourse of the airport. She is understood to have wiped a liquid on his face, which is thought to have been a fast-acting poison.

Another woman is seen approaching him before they both walk away.

A North Korean man, a Vietnamese woman, an Indonesian woman and a Malaysian man have been arrested in connection with Kim Jong-nam’s death, and Malaysian police are now hunting for four more North Koreans who left the country on the day Kim Jong-nam was attacked.

The probe into Kim-Jong-nam’s death has led to a diplomatic row between Malaysia and North Korea. The country’s ambassador to North Korea has been removed from Pyongyang.

North Korea’s ambassador to Malaysia has insisted that the man who died in the Kuala Lumpur airport is not Kim Jong-nam and that Malaysia’s investigation into the death cannot be trusted.

Ambassador Kang Chol questioned Malaysian authorities’ motives last week when they insisted on carrying out an autopsy before returning the victim’s body to North Korea.

He has been summoned by the Malaysian foreign ministry to explain his comments. In a statement, the ministry said the ambassador insinuated the Malaysian government had “something to conceal”.

“The ambassador also alleged that Malaysia was ‘colluding and playing into the gallery of external forces’,” the statement read.

Malaysia’s Prime Minster has since said the government’s investigation will be “objective”.

“We have no reason why we want to do something to paint North Korea in a bad light, but we will be objective,” he said.