The Malaysian authorities are expected to extend the remand of two female suspects in the murder of Mr Kim Jong Nam, whose death last week sparked a diplomatic row between Malaysia and North Korea.
Prime Minister Najib Razak yesterday rapped North Korean Ambassador Kang Chol, calling his criticism of Malaysia's handling of the investigation on Monday "diplomatically rude".
Four suspects have been arrested in connection with the case, which police have classified as "sudden death". The two women were identified by CCTV footage taken from Kuala Lumpur's airport, where Mr Kim was allegedly assassinated on Feb 13.
The remand order, which expires today, can be extended for another seven days.
On Monday, Mr Kang accused Malaysia of colluding with South Korea in the investigation, and demanded a joint probe as he said Kuala Lumpur could not be trusted.
"The statement by the ambassador was totally uncalled for. It was diplomatically rude. But Malaysia will stand firm," Datuk Seri Najib said yesterday.
"They (North Korea) should help us to find out the truth. That is more important than (making) sweeping and baseless statements," he was quoted as saying by the Bernama news agency.
South Korea, too, has denied the ambassador's claim, calling it "preposterous and sophistic", Yonhap news agency reported, quoting a South Korean ministry official.
"The envoy's comment on South Korea is a preposterous claim that is not even worth countering," said the official.
Embassy officials have asked Malaysia to hand over Mr Kim's body to North Korea, claiming that he died a "natural death" after suffering a heart attack. They also insisted that the dead man was a North Korean citizen whose passport identified him as Kim Chol.
They were also against the autopsy, and said Malaysia's request for a DNA sample from a next of kin was "preposterous".
Mr Kang's statement also drew the ire of Malaysian ministers, including Transport Minister Liow Tiong Lai. "It is nothing short of shocking. This is not the action befitting a diplomat," he said.
Malaysia has recalled its ambassador to Pyongyang.
Police have nabbed four people since last Wednesday - a Vietnamese woman identified as Doan Thi Huong, 29, last Wednesday, and an Indonesian woman, Siti Aisyah, 25, early last Thursday.
Of the two men, one of them is a North Korean national, Ri Jong Chol, 46, who has been in Malaysia on a work visa since 2013, and the other is Muhammad Farid Jalaluddin, 26, the Malaysian boyfriend of Siti Aisyah.
Four North Korean men wanted by Malaysian police are believed to have left the country on the same day as the attack.
The two women told police they were told to play a prank on a man at the airport as part of a television show.
Both Indonesian and Vietnamese officials have asked Malaysia for consular access to the two women.