A gag order has been imposed on the police and potential witnesses from making any public statements on the Kim Jong-nam murder case.

The application was made by Indonesian suspect Siti Aisyah's lawyer Gooi Soon Seng at the Sepang Magistrate's Court today.

Sessions Court judge Harith Sham Mohamed Yasin, sitting as a magistrate, granted the application.

"The defence seeks a gag order on the police and any potential witnesses from making any public statements which can incriminate my client or compromise the defence.

"This is to ensure a fair trial," Gooi told the court.

He added that much has been said about the case, which is sub judice.

Magistrate Harith Sham Mohamed Yasin granted the application.

Up to today, the police have been the main source of information regarding Kim who was murdered on Feb 13.

Siti Aisyah, 25, and Vietnamese Doan Thi Huong, 28, are said to have smeared a toxic substance on the victim at the Kuala Lumpur International Airport (KLIA 2).

It was later established that the assailants had used the VX nerve agent.

Both of them were charged at the Sepang Magistrate's Court today under Section 302 of the Penal Code which carries the death penalty.

Four other accused are at large according to the charge sheet.

No plea has been recorded, and the prosecution has asked for the case to be mentioned again on April 13, to allow them to gather the relevant case facts.

Today's hearing was held under tight security.

Journalists covering the case from inside the courtroom were made to surrender all electronics and had to go through three security checkpoints and two body checks.