Malaysian police have named a senior North Korean embassy official they want to question in connection with the killing of Kim Jong-nam.
Hyon Kwang Song is one of three North Koreans being sought, along with an employee of the state airline.
Police also confirmed Mr Kim, half-brother of North Korean leader Kim Jong-un, died after two women wiped a toxin on him at Kuala Lumpur airport.
North Korea’s embassy in Malaysia angrily denied the claims.
In a statement, it said the fact that the substance was on the hands of the women proved it could not have been a poison and called for the immediate release of the “innocent females” and a North Korean man.
Speaking at a press conference in Kuala Lumpur earlier on Wednesday, Malaysian Police Chief Khalid Abu Bakar said they were looking for three North Koreans in addition to the previously announced suspects.
One of them is Hyon Kwang Song, 44, the second secretary of the North Korean embassy in Kuala Lumpur.
The others are Kim Uk II, 37, who works for Air Koryo, and another North Korean Ri Ju U.
Khalid Abu Bakar said they had written to the North Korean ambassador to Malaysia asking him to allow police to interview Mr Hyon and the other suspects.
If the ambassador does not co-operate, “we will compel them to come to us”, he said, without giving details.
The police chief also said security had been stepped up at the morgue where Kim Jong-nam’s body is being kept after an attempted break-in earlier in the week.
“We knew there were attempts by someone to break into the hospital mortuary. We had to take precautions,” he was quoted by the Malay Mail as saying.