About 10 outdoor surveillance cameras were installed at an Osaka home where 33-year-old Airi Kakimoto was found dead last week after being confined by her parents for around 15 years allegedly due to mental illness, investigative sources said Wednesday.

Police suspect the parents, who were earlier arrested on charges of abandoning the body of their dead daughter, set up the cameras to monitor activity in the area out of fear that her confinement would be discovered.

The dead woman had apparently been monitored by her parents since she was a teenager. Police said an autopsy showed that the daughter had frozen to death and was in a state of extreme malnutrition, weighing only 19 kg.

Her father, Yasutaka, 55, and mother, Yukari, 53, admitted to confining their daughter in a room about 3 square meters in size since she was 16 or 17 years old, saying her mental illness made her violent, according to the police.

The Kakimotos allegedly told police that when they saw — via the surveillance camera — that she was motionless, they went to check on her and found her dead, other investigative sources said Thursday.

The wooden single-story home in Neyagawa is surrounded by a roughly 2-meter-high fence, which makes it difficult to view the inside of the house from outside the property.

In addition to the tiny room where Airi was confined, cameras were installed near a nameplate for the Kakimoto family on the fence and on a utility pole so that the nearby street could be monitored, the sources said.

The couple also allegedly told police that recently they had only fed their daughter once a day before she died around Dec. 18.

According to the police, the parents renovated their house to add the small room fitted with a double door that could be unlocked only from the outside.

Inside the unheated room, there was a makeshift toilet and a tube designed to allow the woman to drink water from a tank set up outside. The room had no windows.

The parents reported the daughter’s death to police on Saturday.

They admitted to keeping her body at the home, saying they wanted to keep her close to them because she was “adorable.”

The sources and Neyagawa Municipal Government also found that neither the parents nor Airi had filed an application for health handbooks for people with disability. Airi had been diagnosed with mental illness.

The city’s division on disability and welfare said health handbooks for mental illness are issued, if an application is filed, for those suffering from this illness for a long time. Depending on the gravity of the condition, the patients or their families can secure the support of home helpers or have their taxes reduced.

The city said it was not aware of Airi’s condition or her confinement.

The revelation suggests that the parents chose to isolate her themselves and not seek government assistance amid what support groups say is an atmosphere of prejudice toward people with mental illnesses.

Some neighbors said they did not know anyone lived there. Those that did said they had hardly any contact with the family.

The National Federation of Mental Health and Welfare Party in Japan, a Tokyo-based group made up of patients with mental illnesses and their families, said there are cases where applications for handbooks for people with disabilities are not filed because they do not want to acknowledge their condition or want to keep it a secret.

“It is not unusual for families of patients suffering from mental illnesses to think that the condition brings shame, and instead choose not to consult anyone and isolate themselves,” said Masako Kageyama, an associate professor of public health and nursing at Osaka University.

Kageyama said it is often “hard to bring the patients to hospitals,” and urged the government to improve visits to homes by doctors to prevent the patient’s condition from worsening.