Pathologist Mohamad Shah Mahmood said it was possible four other suspects who are mentioned in the charge sheet but are still at large could have administered a nerve agent before Kim Jong-Nam was attacked by the women.
Indonesian Siti Aisyah and Vietnamese Doan Thi Huong are on trial accused of smearing poison VX on Kim's face at Kuala Lumpur international airport on February 13, in a Cold War- style hit that stunned the world.
The defendants, both in their 20s, say they were duped into believing they were taking part in a prank for a reality TV show and their lawyers blame North Korean agents.
The murder sparked a fierce row between Malaysia and North Korea, which is suspected of ordering the hit. Pyongyang denies the allegation.
More From This Section
The charge sheet blames Kim's death on the women along with four other people still at large, who are not named. Four North Korean suspects fled Malaysia on the day of the murder.
"The possible route of entry is via skin contact, ingestion, inhalation, injection and via the eye," he told Shah Alam High Court, outside the capital Kuala Lumpur.
The lawyer asked Mohamad Shah if it was possible that the four others mentioned in the charge could have poisoned Kim before the victim arrived at the airport.
"There is a possibility," the pathologist, who carried out the post-mortem on Kim, responded.
CCTV footage of the attack shows the women coming up behind Kim and swiping his face with a substance before running away, and a post-mortem report showed his death was caused by VX.
Earlier, defence lawyers put on face masks and gloves as they examined bags of Kim's blood samples and swabs taken from his face.
A bag containing some of Kim's personal effects, including underwear, was opened, sending an unpleasant smell wafting across the room.
A post-mortem report submitted to the trial yesterday revealed new personal details about Kim, such as that he had several tattoos, including one of a dragon and another of a dragon's head breathing fire.