A former member of the Aum Shinrikyo doomsday cult pleaded not guilty to almost all charges against him, including murder, during the first day of a high-profile trial at the Tokyo District Court on Friday.

The trial of Katsuya Takahashi, 56, revisits the fatal terrorist attack on Tokyo's subway system in 1995 that was masterminded by the cult, and represents the first scrutiny of the case under the lay judge system, introduced in 2009.

The trial is expected to last four months, with a verdict likely at the end of April, according to local media reports.