Kim Jong Nam, the estranged half-brother of North Korea's leader, told a Japanese friend in Malaysia that his life was in danger, six months before his assassination at a crowded Malaysian airport, a court heard Tuesday.

Police investigating officer Wan Azirul Nizam testified in the Shah Alam High Court that the Japanese friend, identified in the witness list as "Tomie Yoshio," quoted Kim as telling him six months before his death, "I am scared for my life."

Azirul, a key prosecution witness, said each time Kim came to Malaysia, his Japanese friend would arrange for his personal driver to pick him up from the airport and take him to wherever he wanted to go.

Kim went to the Kuala Lumpur International Airport's budget terminal in that car on Feb. 13, 2017 to take a flight back to Macau, his base for several years since falling out of favor with his father, the late North Korean leader Kim Jong Il.

When he died in 2011, Kim Jong Il was succeeded by his younger son Kim Jong Un, who is widely thought to have ordered his elder half-brother's assassination to prevent him from challenging his power.

Two women, 26-year old Siti Aisyah from Indonesia and 29-year old Doan Thi Huong from Vietnam, are now on trial for killing Kim by swiping his face with the deadly VX nerve agent. They were charged together with four North Koreans, Hong Song Hac, Ri Ji Hyon, Ri Jae Nam and O Jong Gil, who are still at large, with the murder.

All six were caught on airport security cameras at the crime scene that day. The four North Korean men were seen departing the country just hours after the murder.

Aisyah's lawyer Gooi Soon Seng told the court that the four men were "the real killers" and Aisyah is mere "scapegoat," but Azirul disagreed.

Aisyah had told the police that Hong had paid her $600 each time he asked her to perform a "prank," allegedly for a Japanese YouTube program. They first met at Phnom Penh International Airport on Jan. 21 last year through another North Korean, Ri Ji U.

With Hong, she played several "pranks" at the Cambodian airport, as well as around Kuala Lumpur and at its airport.

Gooi told the court that Hong was a North Korean diplomat based in Jakarta, citing document from Indonesian Foreign Ministry.

The court was previously shown records of text messages retrieved from Aisyah's handphone where Aisyah communicated with Hong in the Indonesian language.