A 70-year-old retired railway employee was found dead and his mentally disabled daughter was found in a frail condition near the body at their residence in Uttar Pradesh's Mahoba.
Additional Superintendent of Police (ASP) Vandana Singh said that the body was found on Monday, and a postmortem examination has been conducted.
"As per the post-mortem report, the cause of death has been found to be chronic lung disease," she said.
The kin of the deceased allege ill-treatment and years of confinement by a couple who were hired for domestic help. An investigation has been launched to look into the matter, officials said.
The deceased, identified as Om Prakash Singh Rathore is a retired senior clerk from the Railways. He lived in Hind Tyre Gali locality of Mahoba town.
His wife Renuka had died in 2016, and the couple's 27-year-old daughter Rashmi is mentally disabled, police said.
Rathore's daughter, who was present at the house, was found in a very weak and distressed condition, Vandana Singh said.
The ASP said serious allegations have been levelled by family members against a couple who had been living in the house, hired for domestic help.
Preliminary findings pointed out that the couple had been working as domestic help for Rathore and his daughter for the past eight to nine years and were responsible for their day-to-day care.
During this period, Rathore had apparently transferred the registered electricity connection of the house in the name of the servant's wife, police said.
The officer also noted that no prior complaint had been made by the family regarding alleged confinement or ill-treatment, nor had any earlier efforts been made by them for Rathore and his daughter's care.
Meanwhile, Rathore's younger brother Amar Singh told reporters that when family members reached the house after learning about his death, they found Rashmi lying near her father's body in a pitiable condition.
He alleged that the couple had effectively taken control of the house and confined Rathore and his daughter to a room on the ground floor.
"For the past three years, they were not allowed to meet anyone. Whenever we tried to visit, the couple would send us back on some pretext," he claimed.
Police said all allegations are being examined and further legal action will be taken based on the findings of the investigation.