The Malaysian health authorities said Mr Kim Jong Nam, half-brother of North Korea's leader, did not die of a heart attack, had no puncture wounds and has not been identified by his next of kin.
Referring to Mr Kim as "the deceased", Health Ministry director-general Noor Hisham Abdullah also refuted claims that a second autopsy was carried out.
"The post-mortem examination was carried out at 12.45pm on Feb 15, 2017, and completed at 6.45pm the same day," he said yesterday.
Datuk Dr Noor Hisham told reporters he could not say when the autopsy results - to determine the cause of death, among other things - will be released as the labs are still analysing tissue samples.
But based on preliminary observations, he said, there is "no evidence of a heart attack" and "there is nothing to suggest puncture wounds or marks".
North Korea's Ambassador to Malaysia, Mr Kang Chol, on Monday insisted that a North Korean citizen whom he referred to as Kim Chol, the name on the passport, "fainted from a heart attack", and called it a "natural death".
South Korean media outlets, which reported Mr Kim Jong Nam's death last Tuesday, said he was killed by a poisoned needle.
Mr Kim, 45, was at the budget terminal of Kuala Lumpur International Airport 2 to take a flight to Macau last Monday when two women walked up to him. One of them wiped his face with a poisonous substance. The women then left quickly.
Mr Kim approached airport staff, complaining that he felt dizzy. He died on the way to hospital.
His body is being kept at the morgue in Hospital Kuala Lumpur amid tight security by a special forces team. Malaysia has said that it cannot release the body until it gets a DNA sample from a family member.
Despite media reports on Monday that Mr Kim's son Kim Han Sol was in Kuala Lumpur, Dr Noor Hisham said yesterday: "At the moment, no one has come forward as the next of kin."