Defense Disputes Nerve Agent Used to Kill North Korean Leader’s Half-Brother

This combo shows a file photo (L) taken on May 4, 2001 of Kim Jong Nam, son of the late-North Korean leader Kim Jong Il, and a file photo (R) of his half-brother, current North Korean leader Kim Jon Un in Pyongyang on May 10, 2016. TOSHIFUMI KITAMURA,ED JONES/AFP/Getty Images

KUALA LUMPUR—Lawyers for two women accused of murdering the estranged half-brother of North Korean leader Kim Jong Un said on Tuesday low enzyme levels in his blood may have been caused by liver disease or hormone pills rather than a lethal nerve agent.

Indonesian Siti Aisyah, 25, and Doan Thi Huong, 28, a Vietnamese, are charged with murdering Kim Jong Nam by smearing his face with VX, a chemical poison banned by the United Nations, at Kuala Lumpur airport on Feb. 13.