A former senior member of Aum Shinrikyo expressed regret over his involvement in the doomsday cult in an interview ahead of the 30th anniversary of its sarin nerve gas attack on the Tokyo subway system.

"I followed him despite thinking it wasn't right," the 59-year-old man said of his devotion to Aum guru Chizuo Matsumoto, who went by the name Shoko Asahara.

"I should have trusted my instincts," he said.

The former Aum member received a prison sentence in the first lay judge trial of the group over his involvement in a February 1995 abduction and an explosion at the former home of a religious scholar the day before the March 20, 1995, sarin gas attack. He served his sentence and was released in 2022.

"Asahara may have had a desire for destruction," he said of the cult leader's orders to carry out the sarin gas attack. He said that Matsumoto may have been seeking to trigger the end of the world based on his teaching that Armageddon was inevitable.

Aum repeatedly produced and used biological weapons such as the bacteria Clostridium botulinum, which causes botulism, and Bacillus anthracis, which causes anthrax, as well as chemical weapons including sarin gas and the VX nerve agent.

The former Aum member said he was not informed of such activities. "I don't know why Asahara started producing poisonous gases, but it may have been for self-defense," he said.

The man joined the cult and donated all of his property to it in 1987 at the age of 21 after feeling that life was meaningless. "I felt free after cutting off ties with society," he recalled.

When he met Matsumoto for the first time, he felt the guru was a "monster" who was able to see through him.

The cult leader's preaching gradually became absurd, claiming that he was subject to poisonous gas attacks by Freemasons and claiming that he would become the king of Japan, prompting the former member to start harboring doubts. Still, the man was unable to leave the group, as it had members whom he had guided.

Being criticized by people outside the cult made him more religious, he added.

The man said that as someone who chose a life not bound to material things in the heat of Japan's asset-driven bubble economic boom, he sympathizes with modern youths who also do not want to have possessions.

Still, he expressed surprise over the existence of what are known as lone wolves who commit terrorist attacks, saying he and others "took action because of Asahara, a charismatic figure."

After being released from prison, the former member found employment. Last month, he completed compensation payments he had promised to family members of the abductee from February 1995.

But he said "there is no end to atonement," adding that he regrets not being able to say during his time in the cult that things were not right.

The man has decided to live the rest of his life in a way that does not repeat his past mistakes.