TOKYO • A Japanese couple have been arrested after allegedly imprisoning their daughter for more than 15 years, before she froze to death aged 33 this month.

Osaka residents Yasutaka Kakimoto, 55, and his wife, Yukari, 53, admitted to locking their daughter Airi in a small room from the age of around 16 or 17, Kyodo News reported yesterday.

An autopsy showed Airi had frozen to death and was extremely malnourished, weighing only about 19kg and 1.45m tall.

The parents told police they confined their daughter because she was mentally ill and acted violently, national broadcaster NHK said, adding that the room - measuring about 3 sq m - had an intercom that the family used to communicate.

They reportedly fed their daughter about once a day.

The parents also kept more than 10 surveillance cameras around their house in a possible attempt to hide their secret, according to newspaper the Yomiuri Shimbun.

Inside the unheated room, there was a makeshift toilet and a tube designed to allow the woman to drink water from a tank placed outside, Kyodo reported.

After reporting her death to police, the couple were initially charged with illegally disposing of a body, but police were also considering other charges including confinement, Kyodo said.

The woman is believed to have died around Dec 18. Sores on her body suggest that she may have been bedridden, sources said.

AGENCE FRANCE-PRESSE