Five people were Thursday found dead in two places in the city, and police suspect a middle-aged person may have killed his family members before committing suicide.
According to police, Shankar Malakar had two wives and families simultaneously.
While the body of his first wife and son was found at his residence at Harinavi, in the southern part of Kolkata, his body along with that of his second wife and son were recovered from Garfa in the southeastern region of the city.
"After murdering his first wife and son at his Harinavi residence last night (Wednesday), Malakar came to Garfa where his second family lived. After killing his son with a knife, he attacked his wife and killed her also," said a police officer.
"There were signs of a scuffle inside the flat. There were stab injuries on the bodies and the flat was bolted from inside. We have recovered a blade and a knife," said Special Commissioner of Police (Crime) Pallab Kanti Ghosh.
Asked whether there was a link between the recovery of the bodies, Ghosh said preliminary investigation reveals a connection.