North Korea's ambassador to Malaysia said Pyongyang would reject any results of a post-mortem examination carried out by Kuala Lumpur on the body of Kim Jong-Nam, the half brother of the North Korean leader.

"The Malaysian side forced the post-mortem without our permission and witnessing. We will categorically reject the result of the post-mortem conducted unilaterally excluding our attendance," Kang Chol told reporters gathered outside the morgue where the body is being held.

It is the first official comment from North Korea since the killing of Kim Jong-Nam at Kuala Lumpur international airport on Monday.

"Today I met with the high officer of the Malaysian police and strongly demanded him to release the body without delay but he rejected our demand," the ambassador said, according to an English transcript of his comments.

Malaysian police were being pressured by hostile forces, notably South Korea, and the post mortem was a violation of human rights, he added.

South Korea has pointed the finger of blame at the North, citing a "standing order" from Kim Jong-Un to kill his sibling and a failed assassination bid in 2012 after he criticised the regime.

Earlier, Malaysia said it would not release the body until a family member provided a DNA sample to prove the dead man's identity, Selangor state police chief Abdul Samah Mat said today.

A police spokesman said: "So far no family member or next of kin has come to identify or claim the body. We need a DNA sample of a family member to match the profile of the dead person.

"North Korea has submitted a request to claim the body, but before we release the body we have to identify who the body belongs to," he added.

Malaysia's deputy prime minister yesterday confirmed that the man was Kim Jong-Nam, the estranged sibling of the North Korean leader, Kim Jong-Un, referring to the passports carried by the man.

Kim Jong-Nam, 45, was believed to have been in Malaysia on a passport bearing the name Kim Chol, a known alias, according to South Korean media.