TOKYO -- Japanese police plan to arrest the leader of a doomsday cult on murder charges after vital new evidence emerged about bags used to unleash deadly nerve gas on Tokyo subways, the Yomiuri newspaper said Thursday.


It said experts identified common features between the plastic bags used to hold gas in the March 20 subway attacks and bags seized at a chemical plant belonging to the Aum Shinrikyo cult in Kamiku Ishiki, a village at the foot of Mount Fuji.


Bags found at the plant, called the "Seventh Satian" after the Sanskrit word for truth, were made from the same material as some of the bags used in the attacks, the paper said. One of two lamination machines seized produced bags with identical edges and patterns, it said.


The evidence could be the vital link investigators need to press charges against the sect and arrest its mysterious leader, Shoko Asahara, over attacks which killed 12 people and injured 5,000. After six weeks of raids on the cult, they have still not pinned down evidence that the cult carried out the subway attacks nor found traces of the sarin gas used.


They have found vast quantities of chemicals and scientific equipment at the Seventh Satian, as well as evidence that sarin was present there.


Around 150 Aum followers have been arrested -- but on grounds unrelated to the attacks, such as confining people against their will -- apparently in the hope that questioning will yield new information.


Police have decided to ask prosecutors for warrants to arrest Asahara and his chemical team on suspicion of murder as soon as a report describing the bag evidence is officially released, Yomiuri said. It did not provide a time frame.


To support their charges, police have testimony from former sect followers that only the sect's chemical team was allowed access to the Seventh Satian, the paper said. Asahara, as a leader who commands unquestioning loyalty and devotion from his followers, should have been in a position to know if sarin was being produced, meaning conspiracy charges could be pressed against him, Yomiuri said.


Many of the chemical team are already in custody, including its head, Masami Tsuchiya, arrested on suspicion of harboring a fugitive.


Asahara's whereabouts, and whether he is still alive, remain a mystery.


The National Police Agency ordered local police chiefs last week to track him down and bring him in for questioning on a voluntary basis.


Aum spokesman Fumihiro Joyu has said Asahara is bedridden with a long-term illness. Joyu said he talks to him regularly by telephone.


On Wednesday, Joyu called an abrupt halt to a news conference held to denounce the arrest of the sect's top lawyer, after reporters asked persistently about the guru's whereabouts.