A Malaysian judge has ruled that there is enough evidence to proceed with the trial of two women charged with the murder of the half-brother of North Korean leader Kim Jong Un.

Doan Thi Huong, 25, from Vietnam and 29-year-old Indonesian Siti Aisyah are accused of assassinating Kim Jong Nam in Kuala Lumpur airport in Malaysia in February last year.

Kim died within 20 minutes of being exposed to the toxic nerve agent VX, which was allegedly smeared on his face by the women as he waited to board a flight to Macau, The Guardian reports.

Speaking on Thursday at Shah Alam High Court outside the capital of Kuala Lumpur, Judge Azmi Ariffin accepted the prosecution’s case that the women, with the help of four individuals who have evaded capture, had caused the death of Kim.

“I must therefore call upon them to enter their defence on their respective charges,” he said.

CNN reports that the defence “will argue the women were tricked into committing murder under the guise of staging pranks for a television show”, and that the real culprits were the North Korean operatives who fled the country immediately after the murder.

The accused say they were approached in Hanoi and Kuala Lumpur in early 2017 while working as escorts, The Guardian reports, and offered roles in a Japanese comedy Youtube show, “where they would perform pranks by smearing lotion on people’s faces”.

Both Siti and Doan deny knowing who Kim was, and both say they were paid hundreds of dollars to take part.

But already, Azmi appears to have his reservations regarding the defendants’ story. The Sydney Morning Herald says that he told the court there was “no hidden crew and no attempt to bring the target in on the joke”, as is usual in prank shows.

"The sole purpose of a prank is fun with no intention to cause any type of harm... the use of the word suggests that the act must get everyone laughing at the end, even the target," Azmi added.

Aisyah’s lawyer Gooi Soon Seng said that the prosecution had failed to demonstrate a motive for the murder and relied instead on “circumstantial evidence”. He also chastised investigators failing to preserve original copies of the security footage as evidence.