While the brothers' bodies were found in a decomposed condition, the sister was found in an unconscious state. She died on way to the hospital, a senior officer said.
"The brothers have been identified as Triloki Prasad Gupta (59) and Bhola Prasad Gupta (53). The sister was identified as Shanti Gupta (56). All the three bodies have been sent for autopsy to ascertain the cause of death," he said.
After locals complained of a foul smell coming from the house, police reached the spot and broke open the door and recovered the bodies.
It is suspected that carbon monoxide emitted from a generator might have suffocated the siblings to death but the exact cause of death will be ascertained only after getting the autopsy report, forensic expert Wasim Reja said.
"They (the three siblings) used to mostly stay indoors. We met the brothers two days back when the power in the house went out due to a short circuit. Yesterday none of them came out. Today some people got a foul smell coming out from the house and informed the police," a local woman said.
"Prima facie no foul play is evident in the incident. The doors were locked from inside. We are investigating all aspects," police added.
( With inputs from IANS )