Indonesian Siti Aisyah and Vietnamese Doan Thi Huong entered their pleas through interpreters at Shah Alam High Court, outside the capital Kuala Lumpur.
The murder charge was read first to Aisyah, 25, who was wearing traditional Malay dress, in the Indonesian language. After conferring with an interpreter, the interpreter indicated she was pleading not guilty.
The charge was then read to Huong, 29, who was wearing a blue jumper, in the Vietnamese language. Her interpreter also told the court she was pleading not guilty.
They are accused of rubbing toxic VX nerve agent in his face. They claim they were duped into believing they were taking part in a prank for a reality TV show.