Police suspect the family to have committed suicide due to financial issues.
The deceased identified as Swaroop G Das, 37, a goldsmith, his wife and their two children including a five-month-old baby boy were found dead last night, they said adding they hailed from Howrah.
"They are suspected to have consumed cyanide and died. The exact reason for taking the extreme step is still not clear. It may be due to some financial problems. The matter is under investigation," Mahankali Police Station Inspector B Ramesh said.
The police reached Mr Das's house and broke open the door only to find him and his family members lying dead, police said adding a case has been registered.