TAIPEI (Taiwan News) — Police discovered a troubling scene when they found three members of a family dead inside an apartment in New Taipei’s Zhonghe District, on Friday (Feb. 3).

The borough chief and local police went to check on the family in the afternoon. After knocking and receiving no response, officers broke down the door to enter the apartment.

Inside, they found the dead bodies of the mother, aged 81, and her two sons, aged 54 and 53. A fourth member of the family, the 83-year-old father, surnamed Yang (楊), was found alive in one of the apartment rooms, reported UDN.

It is understood the father suffers from severe dementia, and the three men of the family were all dependent on the elderly mother, surnamed Chen (陳).

Chen was often seen by neighbors going out to purchase groceries and other items. When neighbors realized they had not seen her or her sons since before the holidays, they began to worry and one of them contacted the local borough chief.

Based on the condition of the mother’s body, investigators believe the mother died no less than three months prior to being found on Friday. The two sons were found in the living room, one lying on the sofa and another on the floor. Their bodies also showed signs of decomposition, but not to the extent of the mother’s.

It is estimated the eldest son died around early January, and the youngest son died around two weeks before being found, which would have been at the start of the Lunar New Year holidays.

Circumstances of the deaths are being investigated, but reports suggest the family members died of an unnamed illness. The New Taipei Social Welfare Department is taking care of the elderly father. A daughter of the family is also reportedly alive and has been contacted to manage the family’s affairs.