Decomposed bodies of four members of a family were found in their apartment in the North 24 Parganas district of West Bengal on Sunday, the police said.
The police suspect that the man, who has been identified as Brindaban Karmakar, 52, first killed his family members by poisoning them and then died by suicide.
The police went to the apartment on MS Mukherjee Road in Khardah after neighbours expressed apprehensions that a foul smell was coming from the flat. They broke open the door to enter the apartment and found the four bodies.
While Mr Karmakar’s body was found hanging from the ceiling, the bodies of his family members — wife Debasree, 17-year-old daughter Debaleena, and eight-year-old son Utsaha — were found in different places in the flat, the police said.
A local Trinamool Congress leader said that the man who operates the water pump in the building went to Mr Karmakar’s flat for a bunch of keys.
“He kept ringing the doorbell but nobody answered. He also noticed a stench and informed the local councillor who alerted the police. Police broke open the door and found the four bodies,” he said.
“It is difficult to know the reason behind this,” he said, adding that the man met them the day after Kali Pujo.
“This incident has shocked people of the neighbourhood,” he said.
According to police, a suicide note was also found in the flat, in which the man claimed that his wife had an extra-marital affair and he could not bear it, so he took the extreme step.
The police said that a forensic team visited the spot, and further investigation is underway.