Kuala LUMPUR, Feb 20 (Reuters) - North Korea's envoy to Malaysia on Monday said the police investigation into last week's murder at Kuala Lumpur's main airport could not be trusted, and insisted the victim was not Kim Jong Nam, the estranged half-brother of North Korean leader Kim Jong Un.

Whereas Malaysian authorities have identified the victim as Kim Jong Nam, North Korean ambassador Kang Chol told reporters the embassy had only ever identified the victim as Kim Chol, based on passport carried by the dead man.

"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," said the ambassador, who had earlier been summoned by the Malaysian foreign ministry to explain other remarks doubting the probe's impartiality.

"The embassy has already identified his identity named Kim Chol, a DPRK citizen, as mentioned in his passports," he added.

(Reporting by Rozanna Latiff; Writing by Kanupriya Kapoor; Editing by Simon Cameron-Moore)