Kim Jong Nam, the estranged half-brother of North Korean leader Kim Jong Un, was killed at Kuala Lumpur International Airport last week. Malaysia's deputy prime minister has previously identified the victim as Kim Jong Nam, though formal identification of the corpse has not taken place.
"The cause of death and identity are still pending," Dr Noor Hisham Abdullah, the director general of health at the Malaysian health ministry, told reporters.
Malaysian police are hunting four North Koreans who fled the country on the day of the attack, having already detained one North Korean man, a Vietnamese woman, an Indonesian woman, and a Malaysian man.
At least three of the wanted North Koreans caught an Emirates flight to Dubai from Jakarta late on the same day, an immigration office official in the Indonesian capital told Reuters. Malaysia's Star newspaper reported that all four had returned to Pyongyang.
South Korean and US officials have said they believe North Korean agents assassinated Kim Jong Nam, who had been living in the Chinese territory of Macau under Beijing's protection.