Japanese traditional Taiko drum sticks
Traditional Japanese taiko drumsticks. Exorcist Sachiko Eto used the sticks to beat to death six of her followers (Reuters)

A self-styled exorcist who beat six cult followers to death to "free them from demons" during necromantic ceremonies, has been hanged in Japan.

Sachiko Eto, 65, was sentenced to death in 2005 after the rotting bodies of four women and two men were discovered by police in her home in Sukagawa, Fukushima Prefecture, in July 1995. She had beaten them to death with Japanese Taiko drum sticks.

"She carried out the beatings while watching the victims die one by one. It was extremely cruel," a prosecutor told Fukushima District Court during the trial.

Eto, a door-to-door cosmetic vendor, became a self-professed God in the early 1990s when people around her started claiming she had curative powers.

Soon a small community of followers, including the woman's daughter and an entire family, started living at Eto's house.

According to the prosecution, the macabre exorcisms began after Eto, then 47, fell in love with the boyfriend of one of her followers, who was 27 years her junior.

Yutaka Nemoto had accompanied his 18-year-old girlfriend to Eto's house to be freed by the "evil spirits" inhabiting her body.

Namoto and Eto began an affair and she targeted her 18-year-old love rival, accusing her of being possessed and ordering that she be beaten with drumsticks to cast out her demons.

Eto, Namoto and Eto's daughter Sekine, beat the girl in turn for three days until she was eventually rescued by her parents.

According to the prosecution, this triggered "group bullying" of her followers, subjecting several of them to the bizarre drumstick exorcism ceremonies eventually killing them.

"[Eto] tried to make herself a deified ruler and killed people who threatened her authority in her bid to stop her lover Nemoto from being taken by a female follower," the prosecutor said.

Such was the mental grip the woman held on her followers that in one case one of the followers, Mitsuo Sekine, actively took part in the exorcism that killed his wife Kimiko.

Six people eventually died from the beatings received in the dark rites. Their bodies were left to rot in a room at Eto's house before being discovered by police during a raid.

"I did it as part of a religious service. I never thought they were going to die," Eto pleaded at her trial.

The self-styled exorcist was sentenced to death, while her daughter and Nemoto were given life term jail sentences and Sekine was ordered to serve 18 years in prison.

Eto was hanged by Japanese authorities, together with 39-year-old Yukinori Matsuda, who killed two people during a robbery in 2003.

Another five inmates have been executed by in Japan in 2012. Alongside the US, Japan is one of the few democratic and industrialized countries to enforce capital punishment.

According to the Justice Ministry 131 convicts are currently awaiting execution.