A car with Chiba Prefecture license plates was seen parked in front of Aum Shinrikyo's Nagoya chapter building about 12 hours after a woman was set free in the city after being abducted in Narashino, Chiba Prefecture, investigative sources said Thursday.

The victim, a 19-year-old college student, is the sister of a teenager killed in the 1994 nerve gas attack in Matsumoto, Nagano Prefecture.

She was freed in Nagoya uninjured, 12 hours after her abduction from the street outside her home, according to police.

Her brother, Yuta Abe, was among seven people killed and 144 injured in the gas attack, for which Aum members are now on trial.

Fourteen cultists have been indicted over the gassing, and the 19-year-old's father, Kazuyoshi Abe, 57, is a plaintiff in a case seeking damages for the death of his son and other victims of the attack.

According to witness reports, the car was a green, two-door sports car with Narashino license plates, the sources said.

The engine was running, and a man who appeared to be in his 30s with short hair was sitting in the driver's seat of the left-hand drive car. He was leafing through a thick notebook and talking into a cellular phone, the witnesses were quoted as saying.

A woman who has been active as a Nagoya chapter member then came out of the building and headed north on a bicycle, and the car slowly followed, according to sources quoting witness reports.

Aum has released a statement denying the cult was involved in the abduction.

Chiba Prefectural Police said Thursday that they have set up an investigation headquarters for the crime and assigned 80 investigators to the probe.

They said Aum is one of their investigation targets.

Police said the college student was apparently subdued with chloroform by a man immediately after leaving her home at around 8 a.m. Tuesday, and taken to a car where she was blindfolded.