KUALA LUMPUR - North Korea and Malaysia on Monday locked horns over the investigation into the killing of leader Kim Jong-Un's brother, as footage emerged of the moment he was fatally attacked in a Kuala Lumpur airport.

Malaysia's probe has put five North Koreans in the frame for the airport assassination of Kim Jong-Nam, but Pyongyang said it had no faith in the investigation and claimed Kuala Lumpur was in cahoots with "hostile forces".

The diplomatic confrontation gathered pace Monday when Malaysia recalled its envoy to North Korea and summoned Pyongyang's ambassador Kang Chol for a dressing down. But an unbowed Kang hit back. "It has been seven days since the incident, but there is no clear evidence on the cause of death and at the moment we cannot trust the investigation by the Malaysian police", he told reporters in the Malaysian capital.

The Malaysian response to the ambassador's press conference was equally blunt, with Foreign Minister Anifah Aman saying North Korea's complaints were based on "delusions, lies and half-truths".

Any suggestion that the investigation had a political motive was "deeply insulting to Malaysia", he said.

Pyongyang has also criticised Malaysia for carrying out a post-mortem examination without North Korean permission - a complaint Kuala Lumpur said was groundless.

"The ministry emphasised that as the death occurred on Malaysian soil under mysterious circumstances, it is the responsibility of the Malaysian government to conduct an investigation to identify the cause of death," the foreign ministry said.

Malaysian Prime Minister Najib Razak backed those running the probe, saying it was "very professional".