The North Korean embassy has accused Malaysia of being "extremely insulting" of its sovereignty with regard to the investigation concerning Kim Jong-nam's murder.

The response comes in the wake of Foreign Minister Anifah Aman describing North Korean ambassador Kang Chol's comments accusing Malaysia of not being impartial in the investigation as "insulting" and Prime Minister Najib Abdul Razak chiding the envoy for being rude.

In a statement released this afternoon, the embassy again accused Malaysia of trying to pin the blame on North Korea, by among others, going with the name and identify of the deceased as claimed by South Korea.

It also took issue that Malaysia was requesting Jong-nam's next of kin to provide a DNA sample to positively confirm the identity of the deceased.

"This is extremely insulting to the sovereignty of the Democratic People's Republic of Korea, an illegal act infringing international laws and customs and the diplomatic privileges and at the same time clear evidence that Malaysia takes side with the South Korean allegations," it said.

Referring to Anifah's statement, the embassy said that an impartial investigation should have been based on statements made by the two women suspects and criminal evidence.

"It has been 10 days since the incident happened but Malaysian police has not found any evidence from the arrested suspects.

"In case Malaysia is not influenced by the baseless allegations by South Korea or foreign media, they should respect us in the investigation," it said.

Inspector-general of police Khalid Abu Bakar had this morning rejected North Korea's demands for involvement in the investigation.

Jong-nam died on Feb 13 after an unidentified substance was smeared on his face by a woman at KLIA2.